data via REST API - KamarajuKusumanchi/market_data GitHub Wiki
- Alpha Vantage
- google, yahoo, stooq - may be deprecated in the future
- IEX - not many symbols
Sample link - https://www.alphavantage.co/query?function=TIME_SERIES_INTRADAY&symbol=MSFT&interval=1min&apikey=demo
- http://www.financial-hacker.com/bye-yahoo-and-thank-you-for-the-fish/ - gives various alternatives to Google and Yahoo.