Data Sources

Real-time and historical market-data APIs for US stocks, forex and crypto. The free tier is rate-limited, a key is available on sign-up, and it suits individuals getting started with quant research.

A professional-grade market-data API for US stocks, options, forex and crypto, offering both tick-level and aggregated data. The free tier is delayed; paid tiers provide full real-time access.

A market-data API covering global stocks, forex, crypto and indices, with real-time and historical data plus many technical indicators. The free tier has a daily call cap.

Formerly Quandl, this platform aggregates global stock, futures, macro and alternative datasets — some free, some by paid subscription — accessed via an API and key.

An open-source Python financial-data library that aggregates public data for A-shares, HK stocks, US stocks, futures and macro. Free, no key required, with active community maintenance.

A free securities-data platform offering A-share historical candles, adjustment factors and fundamentals via a Python interface, with no key registration required.

One of China's leading finance portals; its web endpoints provide A-share, fund, futures and capital-flow data — free, no key required — and are commonly used to scrape real-time quotes.

A veteran finance portal whose public quote endpoints provide real-time prices for A-shares, HK and US stocks. Free, no key required, and widely used by the quant community for its stability and simplicity.

China's mainstream institutional financial-data terminal, covering the full range of stocks, bonds, futures and macro. The data is authoritative and comprehensive; access requires a paid terminal license and is then used via its interface.

Hithink's institutional-grade financial-data terminal, covering stocks, bonds, futures and macro, with an Excel plugin and an API. Access requires a paid license.

A leading crypto data platform providing prices, market caps, volumes and exchange data. The public API is free to use; high-frequency or commercial use requires a key.

A major crypto exchange offering public market-data APIs for spot and contracts. Candles, order-book depth and tick data are free to fetch, and the market endpoints need no key.

A leading US-regulated crypto exchange offering public spot market-data APIs. You can fetch prices, candles and trade data for free, and the market endpoints need no key.

A well-known forex broker offering real-time and historical market-data APIs for major currency pairs and CFDs. After opening an account, you call it with a token — well suited to forex quant work.

A free download site for historical data on global stocks, indices, forex and commodities, with direct CSV export and no key registration — commonly used for bulk data pulls for backtesting.