Question: Is there a financial data API that can provide 30 years of historical data for US markets and support large-scale analytics?

If you're looking for a financial data API that offers 30 years of historical data for US markets and that can handle big-impact analytics, Alpha Vantage is a good option. It offers real-time and historical data for stocks, options, forex, commodities and cryptocurrencies in JSON and CSV formats. With more than 50 technical indicators and multiple data endpoints, it's good for both casual and serious users. Alpha Vantage also offers detailed technical analysis with chart-ready time series and supports intraday, daily, weekly and monthly quotes.

Another good option is Finnhub, which offers institutional-grade real-time financial data and alternative data. It covers multiple asset classes including stocks, ETFs, Mutual Funds, Indices, Futures, Options, Currencies and Cryptocurrencies. Finnhub's infrastructure is designed for high availability and scalability, so it can handle big-impact analytics. It also offers technical analysis, alternative data like earnings call transcripts and news sentiment, and real-time market data updates, so it's good for developers, financial analysts and traders.

For a more enterprise-level option, check out LSEG Data & Analytics. The platform offers broad cross-asset data and AI-powered analytics with real-time user-defined parameters. LSEG's cloud-based data and feed distribution system can handle a wide range of users, including wealth advisors and portfolio managers. It also offers access to Reuters news and has an integrated Python scripting environment for creating Jupyter notebooks with analytics and workflows powered by LSEG APIs and data.

Finally, Quilt Labs offers a financial research platform that combines AI to help you find insights and extract data from a unified database of more than two decades of financial information. It comes with advanced keyword search tools and can extract data from SEC financial filings, live newswires and event transcripts. Quilt Labs offers on-premise security and custom solutions, so it's a good option for serious financial analysis.