Ask HN: What are the data needed for quantitative trading?

Probably start with some api. Check out Quantopian https://www.quantopian.com/help or IEX https://iextrading.com/trading/market-data/.

This subreddit has a lot of information https://www.reddit.com/r/algotrading

Type: Prices/Volume, Company Fundamental Data (EPS Growth, P/E Ratio, ROI), News (Earnings, New CEO, Divestiture, Weather), "Alternative Data" (Satellite Images, Transactions)

Vendors: Bloomberg, Thomson (Refinitiv), Factset, Compustat, CapitalIQ, Quandl

Quality: varies, you get what you pay for, cost anywhere from $100's to $100,000's/yr

https://www.quantopian.com/

^ probably good place to start