Stock index S&P 500, showing the dynamics of the US market, as well as a ticker GLD, reflecting the dynamics of world gold prices
This online application uses the stock index S&P 500, that is, the index, whose basket includes 500 largest companies, whose shares are traded on the largest US stock exchanges (NYSE and NASDAQ), . For , it reflects quite well the dynamics of the US stock market as a whole. In view of the fact that the exchange traded fund SPDR S&P 500 (ticker SPY) with high accuracy repeats the dynamics of the S&P 500 (and for the indexes are important dynamics of changes, and not their absolute values), in fact, SPY is used here, including for reason that in the graphical viewer the price chart of its shares can be displayed for visual comparison and calculation of correlations along with any other ticker:
In addition, the SPY shares price chart can easily be imposed on the shares price chart of any single ticker and even two:
Similarly, instead of the SPY ticker, you can use the GLD ticker (SPDR Gold Shares — exchange traded fund whose shares is 100% guaranteed by gold) if you want to compare the dynamics of changes in the stock prices of any particular ticker with, in fact, the dynamics of world gold prices:
My graphical viewer will also allow you to compare the relevant graphs and calculate Spearman's correlation with the "silver ticker" SLV (iShares Silver Trust ETF) and other commodity tickers, such as the USO "oil ticker", UNG (United States Natural Gas), SLX (VanEck Vectors Steel ETF), DBB (industrial metals: zinc, aluminum, copper), RJA (raw materials and global commodities), DAG (agricultural products) and many others. Also there are indices DIA (SPDR Dow Jones Industrial Average ETF), SSO (S&P 500, fall), QID (Nasdaq-100, drop) and some others.
Using of stock indices for forecasting stock market trends
Stock indices show a general picture of the current state of the market and give an idea of the prevailing mood of its participants, and can (with caution) be used to predict trends in its changes. With respect to the game in the rebound on shares of companies with large and medium capitalization, which are quite strongly correlated with the S&P 500 index, very often the purchase of shares of such companies at the moment when the S&P 500 fell by 4-5% or more leads to the fact that quite soon They can be sold with profit (except for cases of large and long collapses of the entire stock exchange, which occurs quite rarely). For example, in the pictures above two such pronounced rapid falls in the index S&P 500 (in February and June 2016) coincided with a decrease in the price of shares of Microsoft and Apple, after which these shares rose rapidly in price. Thus, predicting the dynamics of the US stock market using the S & P 500 index in such cases will almost always be very accurate.