Federal Reserve Bank of St. Louis · Market & fundamentals data
In-depth entry
Free economic database from the St. Louis Fed aggregating hundreds of thousands of US and international time series, with graphs, vintages (ALFRED), an Excel add-in and a keyed JSON/XML API
Massive (Polygon.io, Inc.) · Market & fundamentals data
Market data platform (renamed from Polygon.io in October 2025) with REST and WebSocket APIs, flat files and SQL access for US stocks, options, indices, forex, crypto and futures
Statistics Canada (Government of Canada) · Open & public data
In-depth entry
Canada's national statistical agency publishing census, economic and social data tables with open licensing and programmatic access via Web Data Service
REST API for stock, ETF, options, forex, crypto, commodity and economic data plus fundamentals, news sentiment and technical indicators, with a free key tier and premium plans
Usage-priced market data platform with normalized order-book (MBO/MBP), trades, OHLCV and reference schemas for futures, options and equities, delivered via historical, live and batch APIs in the DBN format
Vendor of historical intraday market data (1-minute to daily bars, tick and options) for US stocks, ETFs, futures, indices, crypto and FX, delivered as zipped CSV bundles under a perpetual licence
Bloomberg L.P. (FIGI Registration Authority) · Market & fundamentals data
Free API and web tool from Bloomberg for mapping tickers, ISINs, CUSIPs and other identifiers to public-domain FIGI instrument identifiers, with search and filter endpoints
The Wharton School, University of Pennsylvania · Market & fundamentals data
In-depth entry
Institution-subscribed research data platform from Wharton hosting CRSP, Compustat, TAQ, OptionMetrics and dozens of other vendors' databases with web queries, SQL, SAS, Python and R access
Ran Aroussi and contributors · Market & fundamentals data
Open-source Python library that downloads price history, fundamentals, options chains and fund data from Yahoo Finance's unofficial endpoints for research and education
Nasdaq's marketplace for financial, economic and alternative datasets (formerly Quandl) with a REST API, time-series and table endpoints and Python, R and Excel clients
Bloomberg L.P. (FIGI Registration Authority) · Market & fundamentals data
Bloomberg's subscription workstation for market data, news, analytics, messaging and execution, with Excel integration and the BLPAPI library for C++, Java, .NET and Python