Intraday stock market data

This API is the only intraday historical API available to the public that has very high intraday resolution since the year 2004 for 660 stocks. This should a provide a unique API for algorithmic trading developers to back-test their strategies. This API provides stock market data in 30 minutes and one hour interval. Also, SPX data is available in 1 hour, 30 minutes, 5 minutes and 1 minute resolution.