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Yahoo Finance

Introduction

Yahoo Finance is an excellent source of free market data and analytics covering both domestic and international markets. While not aimed at a professional user, it does offer a rich source of information that is invaluable to the individual investor at a price that cannot be beat, namely free! The Morpheus adapter for Yahoo Finance provides users a programmatic mechanism to capture some of this data for further analysis which may be helpful for informing your own investment decisions.

Yahoo Finance does not provide any officially supported APIs, so this adapter is essentially reverse engineered from the actions one can affect on the website itself. For that reason, the adapter could break at anytime, and could take some time to fix or perhaps become unsupportable altogether. Accordingly, the suggestion is to only rely on this code for personal non critical research projects.

Data Access

The Morpheus Yahoo Finance adapter includes various DataFrameSource implementations that provide access to asset prices, asset returns, equity fundamentals, option prices and FX rates using DataFrames. In particular, daily historical quote bars (Open, High, Low, Close, Volume) in both dividend adjusted and unadjusted formats are available, as well as intraday delayed quotes while markets are trading. For those of you interested in option markets, expiry dates given an underlying ticker are accessible along with intraday delayed quotes which include an implied volatility estimate. Finally, equity fundamental data can be accessed programmatically from the key statistics page of any security accessible on the site.

The following sections provide some useful examples of how to leverage the API and illustrate some commonly used techniques for analyzing portfolios of investment securities. Firstly, to leverage the library in your project, the following dependency should be included in your build tool of choice.

<dependency>
    <groupId>com.zavtech</groupId>
    <artifactId>morpheus-yahoo</artifactId>
    <version>${VERSION}</version>
</dependency>

There are two ways to integrate with the library, either via a convenience API which involves instantiating an instance of the YahooFinance class or by using the various DataFrameSource implementations directly. In the latter case, the sources should be pre-registered in some initializer as follows.

static {
    DataFrameSource.register(new YahooOptionSource());
    DataFrameSource.register(new YahooQuoteHistorySource());
    DataFrameSource.register(new YahooQuoteLiveSource());
    DataFrameSource.register(new YahooReturnSource());
    DataFrameSource.register(new YahooStatsSource());
}

Historical Quotes

For most securities represented on Yahoo Finance, it is possible to download historical quote bars into a CSV file, and Morpheus leverages this same interface to capture Open, High, Low, Close and Volume data in a DataFrame. Historical price quotes are most often used to compute asset returns, so Yahoo presents these historical prices in both dividend and split adjusted terms making it easy to compute returns that incorporate these affects. The code below downloads split adjusted end of day quotes over the past 10 years for BlackRock, and plots the close price series.

String ticker = "BLK";
YahooQuoteHistorySource source = DataFrameSource.lookup(YahooQuoteHistorySource.class);

//Load end-of-day quote bars and select close price series
DataFrame<LocalDate,YahooField> closePrices = source.read(options -> {
    options.withStartDate(LocalDate.now().minusYears(10));
    options.withEndDate(LocalDate.now());
    options.withDividendAdjusted(true);
    options.withTicker(ticker);
}).cols().select(YahooField.PX_CLOSE);

//Create area plot of close prices
Chart.create().asSwing().withAreaPlot(closePrices, false, chart -> {
    chart.plot().axes().domain().label().withText("Date");
    chart.plot().axes().range(0).label().withText("Close Price");
    chart.title().withText(ticker + ": Close Prices (Last 10 Years)");
    chart.legend().off();
    chart.show();
});

In the example we requested dividend adjusted prices which are convenient for computing returns, however these are artificially changed and do not reflect actual observed prices at the time. To query for unadjusted prices simply pass false as the last parameter to getQuoteBars(). The code below pulls both adjusted and unadjusted prices, then selects the close prices from each frame and plots them for comparison. BlackRock is a high paying dividend stock, so we would expect to see material differences in the two price series.

String ticker = "BLK";
YahooQuoteHistorySource source = DataFrameSource.lookup(YahooQuoteHistorySource.class);

//Load both adjusted and unadjusted quotes
DataFrame<LocalDate,String> frame = DataFrame.combineFirst(
    Stream.of("Adjusted", "Unadjusted").map(style -> source.read(options -> {
        options.withStartDate(LocalDate.now().minusYears(10));
        options.withEndDate(LocalDate.now());
        options.withDividendAdjusted(style.equals("Adjusted"));
        options.withTicker(ticker);
    }).cols().select(YahooField.PX_CLOSE).cols().mapKeys(column -> style))
);

//Plot close prices from both these series
Chart.create().asSwing().withLinePlot(frame, chart -> {
    chart.plot().axes().domain().label().withText("Date");
    chart.plot().axes().range(0).label().withText("Close Price");
    chart.title().withText(ticker + ": Adjusted & Unadjusted Close Prices");
    chart.legend().bottom();
    chart.show();
});

Netflix currently does not pay a dividend, so if we ran this code for NFLX, the two series should be coincident.

Asset Returns

Investment decisions fundamentally boil down to making a judgement call regarding future asset returns, and the likely volatility of those returns over the investment horizon. While Yahoo Finance does not provide an API to directly download asset returns, the ability to capture dividend and split adjusted prices makes it very easy to compute returns. The Morpheus adapter for Yahoo Finance provides an API to calculate daily, weekly, monthly and cumulative returns as demonstrated in the following sections.

Cumulative Returns

Consider 6 major asset classes, namely Emerging Market Equities, Real-Estate, International Equities (outside US), Commodities, Large Blend and Fixed Income. The returns for these asset classes can be proxied using well known liquid ETFs from the likes of Vanguard, BlackRock or State Street Global Advisors among others. For this example, let's use the following tickers.

Ticker Name Provider
VWO Vanguard FTSE Emerging Markets ETF Vanguard Details
VNQ Vanguard REIT ETF Vanguard Details
VEA Vanguard FTSE Developed Markets ETF Vanguard Details
DBC PowerShares DB Commodity Tracking ETF Powershares Details
VTI Vanguard Total Stock Market ETF Vanguard Details
BND Vanguard Total Bond Market ETF Vanguard Details

The code below demonstrates how to use the YahooReturnSource to calculate cumulative returns for these tickers including the effect of any splits and dividend payments. To make the plot more user friendly, we re-label the columns as asset class names rather than the ticker symbols.

YahooReturnSource source = DataFrameSource.lookup(YahooReturnSource.class);
DataFrame<LocalDate,String> returns = source.read(options -> {
    options.withStartDate(LocalDate.now().minusYears(10));
    options.withEndDate(LocalDate.now());
    options.withTickers("VWO", "VNQ", "VEA", "DBC", "VTI", "BND");
    options.cumulative();
}).cols().mapKeys(column -> {
    switch (column.key()) {
        case "VWO": return "EM Equities";
        case "VNQ": return "Real-estate";
        case "VEA": return "Foreign Equity";
        case "DBC": return "Commodities";
        case "VTI": return "Large Blend";
        case "BND": return "Fixed Income";
        default:    return column.key();
    }
}).applyDoubles(v -> {
    return v.getDouble() * 100d;
});

Chart.create().asSwing().withLinePlot(returns, chart -> {
    chart.title().withText("Major Asset Class Cumulative Returns Last 10 Years (ETF Proxies)");
    chart.plot().axes().domain().label().withText("Date");
    chart.plot().axes().range(0).label().withText("Return");
    chart.plot().axes().range(0).format().withPattern("0.##'%';-0.##'%'");
    chart.legend().on().bottom();
    chart.show();
});

Some of the potential take aways from this chart are as follows:

Smoothed Returns

On a day-to-day basis, market prices are extremely noisy and for the most part completely random. It is often useful to remove some of this noise by smoothing the returns, which in turn develops a more stable signal which can be consumed by a systematic investment process. The Morpheus adapter supports smoothing returns based on an Exponential Weighted Moving Average (EWMA) which is a commonly used technique in signal processing.

The code below generates cumulative returns for the S&P 500 Index tracker with ticker symbol SPY, and smooths the data with various half-lives, namely 0, 5, 10, 30 and 60 business days. A 0 day half-life is interpreted as no smoothing, so this simply yields the raw data. The smoothed signal is computed as follows:

$$ S_{t} = \alpha x_{t} + (1 - \alpha) S_{t-1} \ for \ t > 0 \ and \ where \ S_{0} = x_{0} $$

There are various ways to compute \( \alpha \), but in Morpheus we calculate it based on a half-life as follows:

$$ \alpha = 1 - e^{log(0.5) / halfLife} $$

String ticker = "SPY";
YahooReturnSource source = DataFrameSource.lookup(YahooReturnSource.class);
Array<Integer> halfLives = Array.of(0, 5, 10, 30, 60);
DataFrame<LocalDate,String> frame = DataFrame.combineFirst(halfLives.map(halfLife -> {
    return source.read(options -> {
        options.withStartDate(LocalDate.now().minusYears(5));
        options.withEndDate(LocalDate.now());
        options.withTickers(ticker);
        options.withEmaHalfLife(halfLife.getInt());
        options.cumulative();
    }).cols().replaceKey(ticker, String.format("%s(%s)", ticker, halfLife.getInt()));
}));

Chart.create().withLinePlot(frame.applyDoubles(v -> v.getDouble() * 100d), chart -> {
    chart.title().withText(String.format("%s EWMA Smoothed Returns With Various Half-Lives", ticker));
    chart.plot().axes().domain().label().withText("Date");
    chart.plot().axes().range(0).label().withText("Return");
    chart.plot().axes().range(0).format().withPattern("0.##'%';-0.##'%'");
    chart.legend().on().bottom();
    chart.show();
});

It's clear from the plot below that the larger the half-life the more smoothing is applied, which makes sense based on the expression for half-life above.

Return Distribution

Many of the statistical techniques in modern finance are predicated on the assumption that asset returns are normally distributed. However, it is often the case that returns are not normal, which is why during the GFC many funds experienced greater than -6 sigma events one day after the next. While returns are not normal, the statistical techniques that are commonly used are still a reasonable engineering approximation when markets are not under stress. When they are under stress, all bets are off (no pun intended), which can lead to bad outcomes for investors.

The code below computes daily returns for the S&P 500 ETF tracker with ticker symbol SPY over the past 20 years, and then generates a histogram of these returns using 200 bins. In addition, the mean and standard deviation of these daily returns are calculated. They are then used to compute a normal probability density function which is scaled appropriately and then overlaid on the chart.

String ticker = "SPY";
YahooReturnSource source = DataFrameSource.lookup(YahooReturnSource.class);
DataFrame<LocalDate,String> returns = source.read(options -> {
    options.withStartDate(LocalDate.now().minusYears(20));
    options.withEndDate(LocalDate.now());
    options.withTickers(ticker);
}).applyDoubles(v -> {
    return v.getDouble() * 1d;
});

double binCount = 200;
double min = returns.stats().min();
double max = returns.stats().max();
double mean = returns.stats().mean();
double stdDev = returns.stats().stdDev();
double bound = Math.max(Math.abs(min), Math.abs(max));
double scale = ((max - min) / binCount) * returns.stats().count();
DataFrame<Double,String> normDist = normal("NDIST", -bound, bound, (int)binCount, mean, stdDev, scale);

Chart.create().withHistPlot(returns, (int)binCount, chart -> {
    chart.title().withText(ticker + ": Daily Return Frequency Distribution");
    chart.subtitle().withText(ticker + " Returns over past 20 years");
    chart.plot().<String>data().add(normDist);
    chart.plot().style("NDIST").withColor(Color.BLACK).withLineWidth(2f);
    chart.plot().render(1).withLines(false, false);
    chart.plot().axes().domain().label().withText("Return");
    chart.plot().axes().domain().format().withPattern("0.00'%';-0.00'%'");
    chart.plot().axes().range(0).label().withText("Frequency");
    chart.show();
});

A couple of features regarding the fit standout immediately, namely that the actual distribution has a higher central peak and the shoulders are a bit narrower. The standard deviation of SPY daily returns over the past 20 years comes out to be 1.239%, and the plot suggests that the fit is a reasonable approximation between +/-3%, or say a little less than +/-2.5 standard deviations (2.5 sigma). The fitted distribution predicts that a -2.5 sigma event, or a one day drop in the S&P 500 of approximately -3.1% has a probability of 0.5733%, which on the assumption of 252 trading days a year is likely to happen once in 175 days or about 1.44 times per year. This is not inconsistent with the actual frequency distribution as shown in the second plot below, which is zoomed into the left side of the distribution inorder to magnify this part of the plot.

Where the normal distribution is a wholly inadequate model is in the space beyond +/- 2.5 sigma. As mentioned earlier, many funds experienced -6 sigma events or greater during the global financial crisis, day after day. The S&P 500 fitted distribution presented above suggests that such an extreme event is likely to occur with a probability of 8.2934E-8% implying it should only happen once in 4,784,799 years! The plot below zooms into the left tail of the distribution demonstrating that extreme events occur far more frequently than a normal distribution would suggest.

In the above example we leverage a function called normal() to generate a scaled normal distribution that we can superimpose on the plot to get a sense of how well the return histogram fits such a model. The code below simply generates a normal curve given the mean, standard deviation of the daily returns, with an appropriate scale factor to fit the histogram.

$$ f(x | \mu, \sigma^2) = \frac{1}{\sqrt{2 \pi \sigma^2}} e^{-\frac{(x - \mu)^2}{2 \sigma^2}} $$

/**
 * Returns a single column DataFrame containing values generated from a normal distribution probability density function
 * @param label     the column key for the PDF series
 * @param lower     the lower bound for PDF
 * @param upper     the upper bound for PDF
 * @param count     the number of values to include
 * @param mean      the mean for the distribution
 * @param sigma     the standard deviation for the distribution
 * @return          the DataFrame of Normal PDF values
 */
@SuppressWarnings("unchecked")
<C> DataFrame<Double,C> normal(C label, double lower, double upper, int count, double mean, double sigma, double scale) {
    final double stepSize = (upper - lower) / (double)count;
    final Range<Double> xValues = Range.of(lower, upper, stepSize);
    return DataFrame.of(xValues, (Class<C>)label.getClass(), columns -> {
        columns.add(label, xValues.map(x -> {
            final double part1 = 1d / (sigma * Math.sqrt(2d * Math.PI));
            final double part2 = Math.exp(-Math.pow(x - mean, 2d) / (2d * Math.pow(sigma, 2d)));
            return part1 * part2;
        }));
    }).applyDoubles(v -> {
        return v.getDouble() * scale;
    });
}

Return Distribution (Smoothed)

Consider the same setup as in the prior example, but in this case we look at the frequency distribution of daily returns after they have been exponentially smoothed with a 20 day half-life. De-noising the returns does not yield a better fit, and the positive skew in the distribution becomes more apparent. In addition, while there is a positive skew, it is also clear that smoothing the returns highlights far more negative extreme events than positive events.

String ticker = "SPY";
int halfLife = 20;
YahooReturnSource source = DataFrameSource.lookup(YahooReturnSource.class);
DataFrame<LocalDate,String> returns = source.read(options -> {
    options.withStartDate(LocalDate.now().minusYears(10));
    options.withEndDate(LocalDate.now());
    options.withTickers(ticker);
    options.withEmaHalfLife(halfLife);
}).applyDoubles(v -> {
    return v.getDouble() * 100d;
});

double binCount = 200;
double min = returns.stats().min();
double max = returns.stats().max();
double mean = returns.stats().mean();
double stdDev = returns.stats().stdDev();
double bound = Math.max(Math.abs(min), Math.abs(max));
double scale = ((max - min) / binCount) * returns.stats().count();
DataFrame<Double,String> normDist = normal("NDIST", -bound, bound, (int)binCount, mean, stdDev, scale);

Chart.create().withHistPlot(returns, (int)binCount, chart -> {
    chart.title().withText(String.format("%s: Smoothed Daily Return Distribution (HL: %s)", ticker, halfLife));
    chart.plot().<String>data().add(normDist);
    chart.plot().style("NDIST").withColor(Color.BLACK).withLineWidth(2f);
    chart.plot().render(1).withLines(false, false);
    chart.plot().axes().domain().label().withText("Return");
    chart.plot().axes().domain().format().withPattern("0.00'%';-0.00'%'");
    chart.plot().axes().range(0).label().withText("Frequency");
    chart.show();
});

Latest Quotes

Accessing a snapshot of the most recent data for one or more securities can be done via a single call using the YahooQuoteLiveSource as shown below. In this example, we request the most recent data for several tickers, and we are presented with a DataFrame containing all available fields as columns. When accessing this data outside of market hours, fields such as the bid/ask price and size will often show NaN values. The resulting DataFrame is keyed by the security ticker along the row axis and YahooField along the column axis allowing fast access to elements of the frame.

YahooQuoteLiveSource source = DataFrameSource.lookup(YahooQuoteLiveSource.class);
DataFrame<String, YahooField> quotes = source.read(options -> {
    options.withTickers("AAPL", "BLK", "NFLX", "ORCL", "GS", "C", "GOOGL", "MSFT", "AMZN");
});
 Index  |  TICKER  |               NAME                |   PX_BID   |  PX_BID_SIZE  |   PX_ASK   |  PX_ASK_SIZE  |    PX_VOLUME    |  PX_CHANGE  |  PX_CHANGE_PERCENT  |  PX_LAST_DATE  |  PX_LAST_TIME  |  PX_LAST   |  PX_LAST_SIZE  |   PX_LOW   |  PX_HIGH   |  PX_PREVIOUS_CLOSE  |  PX_OPEN   |  EXCHANGE  |  AVG_DAILY_VOLUME  |  TRADE_DATE  |  DIVIDEND_PER_SHARE  |    EPS    |  EPS_ESTIMATE  |  EPS_NEXT_YEAR  |  EPS_NEXT_QUARTER  |   FLOAT_SHARES    |  FIFTY_TWO_WEEK_LOW  |  ANNUALISED_GAIN  |     MARKET_CAP      |       EBITDA       |  PRICE_SALES_RATIO  |  PRICE_BOOK_RATIO  |  EX_DIVIDEND_DATE  |  PRICE_EARNINGS_RATIO  |  DIVIDEND_PAY_DATE  |  PEG_RATIO  |  PRICE_EPS_RATIO_CURRENT_YEAR  |  PRICE_EPS_RATIO_NEXT_YEAR  |  SHORT_RATIO  |
-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
  AAPL  |    AAPL  |                       Apple Inc.  |  160.9400  |    1500.0000  |  161.0000  |     800.0000  |  71714046.0000  |    -0.6400  |            -0.0040  |    2017-09-12  |      16:00:00  |  160.8600  |      100.0000  |  158.7700  |  163.9600  |           161.5000  |  162.6100  |       NMS  |     26754500.0000  |        null  |              2.5200  |   8.8100  |        9.0200  |        10.8900  |            3.8400  |  5031913000.0000  |            104.0800  |              NaN  |  830880000000.0000  |  70210000000.0000  |             3.7300  |            6.3000  |        2017-08-10  |               18.2600  |         2017-08-17  |     1.5900  |                       17.8300  |                    14.7700  |       1.9000  |
   BLK  |     BLK  |                  BlackRock, Inc.  |       NaN  |          NaN  |       NaN  |          NaN  |    333885.0000  |     4.5300  |             0.0107  |    2017-09-12  |      16:02:00  |  428.5700  |    38358.0000  |  424.6900  |  428.7000  |           424.0400  |  426.1400  |       NYQ  |       513127.0000  |        null  |             10.0000  |  20.8300  |       21.8200  |        24.9100  |            5.8200  |   123755000.0000  |            336.8400  |              NaN  |   69520000000.0000  |   5060000000.0000  |             5.9700  |            2.3300  |        2017-08-31  |               20.5700  |         2017-09-22  |     1.3700  |                       19.6400  |                    17.2000  |       3.1800  |
  NFLX  |    NFLX  |                    Netflix, Inc.  |  185.0600  |     500.0000  |  185.6700  |     200.0000  |   6689568.0000  |     3.4100  |             0.0188  |    2017-09-12  |      16:00:00  |  185.1500  |   199365.0000  |  180.6400  |  185.3300  |           181.7400  |  182.5500  |       NMS  |      7144270.0000  |        null  |                 NaN  |   0.8200  |        1.1900  |         2.0200  |            0.3100  |   424846000.0000  |             93.2600  |              NaN  |   79940000000.0000  |    706920000.0000  |             7.7000  |           25.2100  |              null  |              225.2400  |               null  |     1.9700  |                      155.5900  |                    91.6600  |       3.0700  |
  ORCL  |    ORCL  |               Oracle Corporation  |       NaN  |          NaN  |       NaN  |          NaN  |  13352387.0000  |     0.2800  |             0.0053  |    2017-09-12  |      16:01:00  |   52.7700  |   839129.0000  |   52.4700  |   52.8900  |            52.4900  |   52.6400  |       NYQ  |     13043800.0000  |        null  |              0.7600  |   2.2100  |        2.9500  |         3.1900  |            0.6900  |  3009105000.0000  |             37.6200  |              NaN  |  218290000000.0000  |  14670000000.0000  |             5.7600  |            4.0300  |        2017-07-17  |               23.8800  |         2017-08-02  |     1.9400  |                       17.8900  |                    16.5400  |       1.8400  |
    GS  |      GS  |  Goldman Sachs Group, Inc. (The)  |       NaN  |          NaN  |       NaN  |          NaN  |   3745841.0000  |     4.8900  |             0.0221  |    2017-09-12  |      16:00:00  |  225.9500  |   160193.0000  |  222.0200  |  227.6900  |           221.0600  |  222.5400  |       NYQ  |      3043750.0000  |        null  |              3.0000  |  19.0700  |       18.2300  |        19.9700  |            5.0400  |   350537000.0000  |            157.7700  |              NaN  |   87720000000.0000  |            0.0000  |             2.6600  |            1.1400  |        2017-08-29  |               11.8500  |         2017-09-28  |     1.0600  |                       12.3900  |                    11.3100  |       1.2700  |
     C  |       C  |                  Citigroup, Inc.  |       NaN  |          NaN  |       NaN  |          NaN  |  15495439.0000  |     1.0800  |             0.0160  |    2017-09-12  |      16:00:00  |   68.7900  |  1090112.0000  |   68.1000  |   69.2500  |            67.7100  |   68.2200  |       NYQ  |     16707800.0000  |        null  |              0.8000  |   4.9900  |        5.2200  |         5.9600  |            1.2900  |  2721749000.0000  |             45.1600  |              NaN  |  187420000000.0000  |            0.0000  |             2.8700  |            0.8800  |        2017-08-03  |               13.7700  |         2017-08-25  |     1.2700  |                       13.1800  |                    11.5400  |       0.0200  |
 GOOGL  |   GOOGL  |                    Alphabet Inc.  |  946.0100  |     100.0000  |  947.2300  |     100.0000  |   1284787.0000  |     3.3600  |             0.0036  |    2017-09-12  |      16:00:00  |  946.6500  |   113174.0000  |  937.5000  |  948.0900  |           943.2900  |  946.9200  |       NMS  |      1773140.0000  |        null  |                 NaN  |  27.5900  |       30.5900  |        39.9900  |            9.6000  |   600581000.0000  |            743.5900  |              NaN  |  655910000000.0000  |  32250000000.0000  |             6.5800  |            4.4100  |              null  |               34.3100  |               null  |     1.6200  |                       30.9500  |                    23.6700  |       1.4500  |
  MSFT  |    MSFT  |            Microsoft Corporation  |   74.6800  |     500.0000  |   74.9300  |     100.0000  |  14394850.0000  |    -0.0800  |            -0.0011  |    2017-09-12  |      16:00:00  |   74.6800  |  1682458.0000  |   74.3700  |   75.2400  |            74.7600  |   74.7600  |       NMS  |     22427700.0000  |        null  |              1.5600  |   2.7100  |        3.1700  |         3.5600  |            0.8300  |  7595028000.0000  |             55.9800  |              NaN  |  575200000000.0000  |  30430000000.0000  |             6.4000  |            7.9600  |        2017-08-15  |               27.5600  |         2017-09-14  |     2.3500  |                       23.5600  |                    20.9800  |       1.9500  |
  AMZN  |    AMZN  |                 Amazon.com, Inc.  |  982.8700  |     100.0000  |  985.0000  |     200.0000  |   2481066.0000  |     4.6200  |             0.0047  |    2017-09-12  |      16:00:00  |  982.5800  |    99104.0000  |  975.5200  |  984.6700  |           977.9600  |  983.2700  |       NMS  |      3773170.0000  |        null  |                 NaN  |   3.9300  |        3.9900  |         8.1800  |            1.7700  |   400088000.0000  |            710.1000  |              NaN  |  472010000000.0000  |  12300000000.0000  |             3.1300  |           20.2200  |              null  |              249.8900  |               null  |     6.3700  |                      246.2600  |                   120.1200  |       1.2100  |

Data from this frame can be accessed in a type safe manner as follows:

String name = quotes.data().getValue("AAPL", YahooField.NAME);
double closePrice = quotes.data().getDouble("AAPL", YahooField.PX_LAST);
LocalDate date = quotes.data().getValue("AAPL", YahooField.PX_LAST_DATE);

Usually not all these fields are desired so specific fields can be requested as follows:

YahooQuoteLiveSource source = DataFrameSource.lookup(YahooQuoteLiveSource.class);
DataFrame<String, YahooField> quotes = source.read(options -> {
    options.withTickers("AAPL", "BLK", "NFLX", "ORCL", "GS", "C", "GOOGL", "MSFT", "AMZN");
    options.withFields(
        YahooField.PX_LAST,
        YahooField.PX_BID,
        YahooField.PX_ASK,
        YahooField.PX_VOLUME,
        YahooField.PX_CHANGE,
        YahooField.PX_LAST_DATE,
        YahooField.PX_LAST_TIME
    );
});
 Index  |  PX_LAST   |   PX_BID   |   PX_ASK   |    PX_VOLUME    |  PX_CHANGE  |  PX_LAST_DATE  |  PX_LAST_TIME  |
------------------------------------------------------------------------------------------------------------------
  AAPL  |  160.8600  |  160.9400  |  161.0000  |  71714046.0000  |    -0.6400  |    2017-09-12  |      16:00:00  |
   BLK  |  428.5700  |       NaN  |       NaN  |    333885.0000  |     4.5300  |    2017-09-12  |      16:02:00  |
  NFLX  |  185.1500  |  185.0600  |  185.6700  |   6689568.0000  |     3.4100  |    2017-09-12  |      16:00:00  |
  ORCL  |   52.7700  |       NaN  |       NaN  |  13352387.0000  |     0.2800  |    2017-09-12  |      16:01:00  |
    GS  |  225.9500  |       NaN  |       NaN  |   3745841.0000  |     4.8900  |    2017-09-12  |      16:00:00  |
     C  |   68.7900  |       NaN  |       NaN  |  15495439.0000  |     1.0800  |    2017-09-12  |      16:00:00  |
 GOOGL  |  946.6500  |  946.0100  |  947.2300  |   1284787.0000  |     3.3600  |    2017-09-12  |      16:00:00  |
  MSFT  |   74.6800  |   74.6800  |   74.9300  |  14394850.0000  |    -0.0800  |    2017-09-12  |      16:00:00  |
  AMZN  |  982.5800  |  982.8700  |  985.0000  |   2481066.0000  |     4.6200  |    2017-09-12  |      16:00:00  |

Option Quotes

Market data for listed Options on equities and ETFs is also accessible from Yahoo Finance (for example, listed options on Apple can be accessed here). It is not clear that Yahoo provides a CSV API for this data, so the Morpheus Adapter screen scrapes the relevant information from the HTML page, which obviously makes it somewhat sensitive to changes in the page style.

The code below demonstrates how to query for the expiry dates on options given the underlying security symbol. It then selects the next upcoming expiry date, and queries for all options, including calls and puts for this expiry.

String ticker = "SPY";
YahooFinance yahoo = new YahooFinance();
Set<LocalDate> expiryDates = yahoo.getOptionExpiryDates(ticker);
LocalDate nextExpiry = expiryDates.iterator().next();
DataFrame<String,YahooField> optionQuotes = yahoo.getOptionQuotes(ticker, nextExpiry);

Calls and puts can easily be separated by filtering the Morpheus DataFrame in the usual fashion as shown below.

//Select rows representing CALL options
DataFrame<String,YahooField> calls = optionQuotes.rows().select(row -> {
    final String type = row.getValue(YahooField.OPTION_TYPE);
    return type.equalsIgnoreCase("Call");
});
       Index         |  TICKER  |  OPTION_TYPE  |  EXPIRY_DATE  |  PX_STRIKE  |  PX_LAST   |  PX_CHANGE  |  PX_CHANGE_PERCENT  |   PX_BID   |   PX_ASK   |  PX_VOLUME   |  OPEN_INTEREST  |  IMPLIED_VOLATILITY  |
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
 SPY170915C00050000  |     SPY  |         CALL  |   2017-09-15  |    50.0000  |  187.5000  |     0.0000  |                NaN  |  186.0900  |  189.2100  |      1.0000  |         0.0000  |              0.0000  |
 SPY170915C00055000  |     SPY  |         CALL  |   2017-09-15  |    55.0000  |  195.0100  |     3.0300  |             0.0158  |  193.1200  |  197.1800  |     56.0000  |       686.0000  |             10.7500  |
 SPY170915C00060000  |     SPY  |         CALL  |   2017-09-15  |    60.0000  |  190.0900  |     3.1200  |             0.0167  |  188.1200  |  192.1300  |     38.0000  |       617.0000  |              9.7188  |
 SPY170915C00065000  |     SPY  |         CALL  |   2017-09-15  |    65.0000  |  185.1500  |     5.5800  |             0.0311  |  183.1200  |  187.2600  |     52.0000  |       390.0000  |             10.0625  |
 SPY170915C00070000  |     SPY  |         CALL  |   2017-09-15  |    70.0000  |  180.1100  |     2.2700  |             0.0128  |  178.0000  |  182.2000  |     67.0000  |       142.0000  |              8.0625  |
 SPY170915C00075000  |     SPY  |         CALL  |   2017-09-15  |    75.0000  |  175.0800  |     6.3200  |             0.0374  |  173.0000  |  177.0300  |     18.0000  |       138.0000  |             13.9258  |
 SPY170915C00080000  |     SPY  |         CALL  |   2017-09-15  |    80.0000  |  170.0800  |     6.1700  |             0.0376  |  168.0000  |  172.2500  |     25.0000  |        59.0000  |              7.8125  |
 SPY170915C00085000  |     SPY  |         CALL  |   2017-09-15  |    85.0000  |  165.1500  |     6.0600  |             0.0381  |  163.0000  |  167.0900  |     13.0000  |       182.0000  |             12.6523  |
 SPY170915C00090000  |     SPY  |         CALL  |   2017-09-15  |    90.0000  |  160.0800  |     8.3800  |             0.0552  |  158.0000  |  162.2200  |      8.0000  |       180.0000  |              6.7500  |
 SPY170915C00095000  |     SPY  |         CALL  |   2017-09-15  |    95.0000  |  155.0800  |     6.1700  |             0.0414  |  153.0000  |  157.2000  |      4.0000  |        55.0000  |              6.1875  |
//Select rows representing PUT options
DataFrame<String,YahooField> puts = optionQuotes.rows().select(row -> {
    final String type = row.getValue(YahooField.OPTION_TYPE);
    return type.equalsIgnoreCase("Put");
});
       Index         |  TICKER  |  OPTION_TYPE  |  EXPIRY_DATE  |  PX_STRIKE  |  PX_LAST  |  PX_CHANGE  |  PX_CHANGE_PERCENT  |  PX_BID  |  PX_ASK  |  PX_VOLUME   |  OPEN_INTEREST  |  IMPLIED_VOLATILITY  |
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
 SPY170915P00055000  |     SPY  |          PUT  |   2017-09-15  |    55.0000  |   0.0200  |     0.0000  |                NaN  |  0.0000  |  0.0100  |     10.0000  |      2250.0000  |              8.5000  |
 SPY170915P00060000  |     SPY  |          PUT  |   2017-09-15  |    60.0000  |   0.0200  |     0.0000  |                NaN  |  0.0000  |  0.0100  |     50.0000  |      1912.0000  |              8.0000  |
 SPY170915P00065000  |     SPY  |          PUT  |   2017-09-15  |    65.0000  |   0.0100  |     0.0000  |                NaN  |  0.0000  |  0.0100  |     10.0000  |      4117.0000  |              7.7500  |
 SPY170915P00070000  |     SPY  |          PUT  |   2017-09-15  |    70.0000  |   0.0100  |     0.0000  |                NaN  |  0.0000  |  0.0100  |      5.0000  |      8582.0000  |              7.2500  |
 SPY170915P00075000  |     SPY  |          PUT  |   2017-09-15  |    75.0000  |   0.0100  |     0.0000  |                NaN  |  0.0000  |  0.0100  |      1.0000  |      5598.0000  |              6.8750  |
 SPY170915P00080000  |     SPY  |          PUT  |   2017-09-15  |    80.0000  |   0.0100  |     0.0000  |                NaN  |  0.0000  |  0.0100  |    150.0000  |      3061.0000  |              6.5000  |
 SPY170915P00085000  |     SPY  |          PUT  |   2017-09-15  |    85.0000  |   0.0100  |     0.0000  |                NaN  |  0.0000  |  0.0100  |     14.0000  |      5525.0000  |              6.1250  |
 SPY170915P00090000  |     SPY  |          PUT  |   2017-09-15  |    90.0000  |   0.0100  |     0.0000  |                NaN  |  0.0000  |  0.0100  |      2.0000  |      5638.0000  |              5.8750  |
 SPY170915P00095000  |     SPY  |          PUT  |   2017-09-15  |    95.0000  |   0.0100  |     0.0000  |                NaN  |  0.0000  |  0.0100  |     50.0000  |     22290.0000  |              5.5000  |
 SPY170915P00100000  |     SPY  |          PUT  |   2017-09-15  |   100.0000  |   0.0100  |     0.0000  |                NaN  |  0.0000  |  0.0100  |     99.0000  |     19382.0000  |              5.2500  |

Volatility Smile

One of the most influential inputs to the famous Black-Scholes-Merton option pricing model concerns the future volatility of the returns on the underlying asset. In fact, volatility is so fundamental to option pricing that certain types of option contracts are quoted in volatility units rather than price. Black-Scholes assumes that the volatility of the underlying returns are constant over the term in question, and it also assumes that other characteristics of the option such as the moneyness (how far in or out-of-the-money the option might be), do not influence estimates of future volatility.

In reality, this does not appear to be the case based on observed market prices. A commonly used visualization in option trading is called the Option Volatility Smile, which plots implied volatilities of options with different strike prices for the same expiry date. According to Black-Scholes, these curves should be flat, but in reality they form more of a curve in the shape of a person smiling. That is, implied volatilities for at-the-money options tend to be lower than for deep in-the-money or deep out-the-money options.

The plot below illustrates the volatility smiles for options on the S&P 500 ETF with ticker symbol SPY which has been generated using the Morpheus Yahoo Finance adapter. While various outliers appear to exist, the smile pattern is pretty clear. These outliers are likely to be explained by low volume at the strike prices in question, so the calculated implied volatilities are stale at those points. The other possibility is a mis-pricing of some options at these strikes, but that is fairly unlikely as such differences would be quickly arbitraged away. The code to generate this plot is also shown below.

String ticker = "SPY";
//Instantiate Yahoo convenience adapter
YahooFinance yahoo = new YahooFinance();
//Select last price for underlying
double lastPrice = yahoo.getLiveQuotes(Array.of(ticker)).data().getDouble(0, YahooField.PX_LAST);
//Select call options with strike price within 10% of current market price and non zero vol
DataFrame<String,YahooField> options = yahoo.getOptionQuotes(ticker).rows().select(row -> {
    final String type = row.getValue(YahooField.OPTION_TYPE);
    if (!type.equalsIgnoreCase("CALL")) {
        return false;
    } else {
        final double strike = row.getDouble(YahooField.PX_STRIKE);
        final double impliedVol = row.getDouble(YahooField.IMPLIED_VOLATILITY);
        return impliedVol > 0 && strike > lastPrice * 0.9d && strike < lastPrice * 1.1d;
    }
});

//Select all distinct expiry dates for quotes
Array<LocalDate> expiryDates = options.colAt(YahooField.EXPIRY_DATE).distinct();
//Creates frames for each expiry including only strike price and implied-vol columns
Array<DataFrame<Integer,String>> frames = expiryDates.map(v -> {
    final LocalDate expiry = v.getValue();
    final DataFrame<String,YahooField> calls = options.rows().select(row -> {
        final LocalDate date = row.getValue(YahooField.EXPIRY_DATE);
        return expiry.equals(date);
    });
    return DataFrame.of(Range.of(0, calls.rowCount()), String.class, columns -> {
        columns.add("Strike", calls.colAt(YahooField.PX_STRIKE).toArray());
        columns.add(expiry.toString(), calls.colAt(YahooField.IMPLIED_VOLATILITY).toArray().applyDoubles(x -> {
            return x.getDouble() * 100d;
        }));
    });
});

//Create plot of N frames each for a different expiry
Chart.create().asSwing().withLinePlot(frames.getValue(0), "Strike", chart -> {
    for (int i=1; i<frames.length(); ++i) {
        DataFrame<Integer,String> data = frames.getValue(i);
        chart.plot().<String>data().add(data, "Strike");
        chart.plot().render(i).withLines(true, false);
    }
    chart.plot().render(0).withLines(true, false);
    chart.plot().axes().domain().label().withText("Strike Price");
    chart.plot().axes().range(0).label().withText("Implied Volatility");
    chart.plot().axes().range(0).format().withPattern("0.00'%';-0.00'%'");
    chart.title().withText("SPY Call Option Implied Volatility Smiles");
    chart.legend().on().right();
    chart.show();
});

We can use a slightly modified version of this code to run the analysis for all PUT options, the results of which are plotted below. The same smile pattern is evident, as are the existence of outliers, which is most likely due to the lack of transactions at the strikes in question. Another take-away from these plots is that deep in-the-money options are more expensive from an implied volatility perspective than deep out-the-money options as the smile does not appear to be symmetric in nature.

Key Statistics

Various financial, trading and valuation statistics are made available by Yahoo Finance on the Statistics page for each applicable security. The Morpheus adapter provides a programmatic mechanism to extract this data into a DataFrame which allows for easy cross sectional comparisons between companies. Only current values are available via this interface, historical values are not supported. The code below demonstrates how to extract these statistics for various companies, and then transposes and prints the DataFrame to standard out.

YahooFinance yahoo = new YahooFinance();
Array<String> tickers = Array.of("AAPL", "ORCL", "BLK", "GS", "NFLX", "AMZN", "FB");
DataFrame<String,YahooField> stats = yahoo.getStatistics(tickers);
stats.transpose().out().print(200, formats -> {
    final SmartFormat smartFormat = new SmartFormat();
    formats.setPrinter(Object.class, Printer.forObject(smartFormat::format));
});
           Index            |     BLK      |     NFLX     |     AAPL     |     ORCL     |      GS      |      FB      |     AMZN     |
--------------------------------------------------------------------------------------------------------------------------------------
                MARKET_CAP  |    69.4700B  |    78.7300B  |   825.8200B  |   201.6200B  |    87.4300B  |   498.4800B  |   474.0300B  |
               PE_TRAILING  |     20.5800  |    221.8400  |     18.1500  |     22.0500  |     11.8100  |     38.4200  |    250.9600  |
                PE_FORWARD  |      1.4000  |      1.9800  |      1.4500  |      1.9800  |      1.0900  |      1.2100  |      6.6200  |
         PRICE_SALES_RATIO  |      6.0300  |      7.7300  |      3.6900  |      5.3400  |      2.7100  |     15.0300  |      3.1600  |
          PRICE_BOOK_RATIO  |      2.3500  |     25.2900  |      6.2400  |      3.7400  |      1.1600  |      7.4900  |     20.4000  |
           FISCAL_YEAR_END  |  2016-12-31  |  2016-12-31  |  2016-09-24  |  2017-05-31  |  2016-12-31  |  2016-12-31  |  2016-12-31  |
       MOST_RECENT_QUARTER  |  2017-06-30  |  2017-06-30  |  2017-07-01  |  2017-05-31  |  2017-06-30  |  2017-06-30  |  2017-06-30  |
             PROFIT_MARGIN  |      0.2992  |      0.0355  |      0.2087  |      0.2474  |      0.2644  |      0.3966  |      0.0128  |
          OPERATING_MARGIN  |      0.4205  |      0.0633  |      0.2684  |      0.3519  |      0.3618  |      0.4666  |      0.0231  |
          RETURN_ON_ASSETS  |      0.0138  |      0.0287  |      0.1152  |      0.0671  |      0.0095  |      0.1493  |      0.0283  |
          RETURN_ON_EQUITY  |      0.1174  |      0.1310  |      0.3603  |      0.1830  |      0.0980  |      0.2251  |      0.0967  |
               REVENUE_TTM  |    11.5200B  |    10.1900B  |   223.5100B  |    37.7300B  |    32.2500B  |    33.1700B  |   150.1200B  |
         REVENUE_PER_SHARE  |     70.5300  |     23.6900  |     42.4000  |      9.1700  |     77.9100  |     11.5000  |    314.7300  |
       REVENUE_GROWTH_QTLY  |      0.0570  |      0.3230  |      0.0720  |      0.0280  |     -0.0060  |      0.4480  |      0.2480  |
              GROSS_PROFIT  |    10.9500B  |     2.8000B  |    84.2600B  |    30.2600B  |    30.6100B  |    23.8500B  |    47.7200B  |
                EBITDA_TTM  |     5.0600B  |   706.9200M  |    70.2100B  |    14.6700B  |         NaN  |    18.0800B  |    12.3000B  |
               EPS_DILUTED  |     20.8300  |      0.8200  |      8.8100  |      2.2100  |     19.0700  |      4.4700  |      3.9300  |
      EARNINGS_GRWOTH_QTLY  |      0.0860  |      0.6100  |      0.1180  |      0.1490  |      0.0050  |      0.7060  |     -0.7700  |
                      BETA  |      1.6800  |      0.6300  |      1.4300  |      1.1400  |      1.4400  |      0.5400  |      1.3800  |
                  CASH_MRQ  |     6.2500B  |     2.1600B  |    77.0100B  |    66.0800B  |   732.4800B  |    35.4500B  |    21.4500B  |
            CASH_PER_SHARE  |     38.5300  |      5.0100  |     14.9100  |     15.9700  |     1.8868K  |     12.2100  |     44.6500  |
                  DEBT_MRQ  |     4.9700B  |     4.8400B  |   108.6000B  |    57.9100B  |   404.4600B  |         NaN  |    23.6200B  |
      DEBT_OVER_EQUITY_MRQ  |     16.6300  |    155.3900  |     82.0100  |    106.7500  |    463.8500  |         NaN  |    101.7500  |
             CURRENT_RATIO  |      1.2300  |      1.3100  |      1.3900  |      3.0800  |      1.8000  |     12.3100  |      1.0100  |
      BOOK_VALUE_PER_SHARE  |    182.2100  |      7.2100  |     25.6100  |     13.0200  |    194.4100  |     22.9200  |     48.3600  |
       OPERATING_CASH_FLOW  |     3.3900B  |    -1.9000B  |    64.0700B  |    14.1300B  |   -15.8300B  |    19.3800B  |    17.0600B  |
    LEVERED_FREE_CASH_FLOW  |     3.4500B  |     5.8300B  |    40.6200B  |     9.6300B  |         NaN  |    10.2200B  |    11.1500B  |
                ADV_3MONTH  |   505.7900K  |     6.9300M  |    26.7900M  |    13.1800M  |     3.0200M  |    16.4700M  |     3.6400M  |
                 ADV_10DAY  |   435.9500K  |     5.6800M  |    34.1000M  |    14.5700M  |     3.3800M  |    13.0400M  |     2.7500M  |
        SHARES_OUTSTANDING  |   160.9800M  |   431.7500M  |     5.1700B  |     4.1400B  |   388.2100M  |     2.3700B  |   480.3800M  |
              SHARES_FLOAT  |   123.7600M  |   424.8500M  |     5.0300B  |     3.0100B  |   350.5400M  |     2.3400B  |   400.0900M  |
     OWNER_PERCENT_INSIDER  |      0.0361  |      0.0182  |      0.0008  |      0.2725  |      0.0179  |      0.0175  |      0.1677  |
 OWNER_PERCENT_INSTITUTION  |      0.8775  |      0.8284  |      0.6247  |      0.5984  |      0.7931  |      0.7244  |      0.6234  |
              SHARES_SHORT  |     2.0600M  |    27.8500M  |    40.3100M  |    31.8300M  |     4.5400M  |    20.2500M  |     4.7200M  |
        SHARES_SHORT_RATIO  |      3.1800  |      3.0700  |      1.9000  |      1.8400  |      1.2700  |      0.9700  |      1.2100  |
        SHARES_SHORT_PRIOR  |     2.3100M  |    25.7400M  |    39.1500M  |    35.7800M  |     4.3500M  |    21.8400M  |     5.0600M  |
              DIVIDEND_FWD  |     10.0000  |         NaN  |      2.5200  |      0.7600  |      3.0000  |         NaN  |         NaN  |
        DIVIDEND_FWD_YIELD  |      0.0235  |         NaN  |      0.0158  |      0.0144  |      0.0139  |         NaN  |         NaN  |
         DIVIDEND_TRAILING  |      9.5800  |         NaN  |      2.3400  |      0.6400  |      2.7000  |         NaN  |         NaN  |
   DIVIDEND_TRAILING_YIELD  |      0.0225  |         NaN  |      0.0148  |      0.0121  |      0.0119  |         NaN  |         NaN  |
     DIVIDEND_PAYOUT_RATIO  |      0.4599  |         NaN  |      0.2650  |      0.2896  |      0.1421  |         NaN  |         NaN  |
         DIVIDEND_PAY_DATE  |  2017-09-22  |        null  |  2017-08-17  |  2017-08-02  |  2017-09-28  |        null  |        null  |
          DIVIDEND_EX_DATE  |  2017-08-31  |        null  |  2017-08-10  |  2017-07-17  |  2017-05-30  |        null  |        null  |
           LAST_SPLIT_DATE  |  2007-06-05  |  2015-07-15  |  2014-06-09  |  2000-10-13  |        null  |        null  |  1999-09-02  |

The code below demonstrates how to generate a plot of a small subset of the profitability and return metrics for a number of prominent financial services and technology firms.

YahooFinance yahoo = new YahooFinance();
Array<String> tickers = Array.of("BLK", "GS", "MS", "JPM", "C", "BAC", "AAPL", "NVDA", "GOOGL");
DataFrame<String,YahooField> data = yahoo.getStatistics(tickers);
DataFrame<String,YahooField> stats = data.cols().select(
    YahooField.PROFIT_MARGIN,
    YahooField.OPERATING_MARGIN,
    YahooField.RETURN_ON_ASSETS,
    YahooField.RETURN_ON_EQUITY
).applyDoubles(v -> {
    return v.getDouble() * 100d;
});

Chart.create().withBarPlot(stats.transpose(), false, chart -> {
    chart.title().withText("Profitability & Return Metrics");
    chart.plot().axes().domain().label().withText("Statistic");
    chart.plot().axes().range(0).label().withText("Value");
    chart.plot().axes().range(0).format().withPattern("0.00'%';-0.00'%'");
    chart.legend().right().on();
    chart.show();
});

Portfolio Analysis

There are several examples of how to use the Yahoo Finance adapter to analyze and construct portfolios of risky assets in the section on Modern Portfolio Theory.