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Market data & broker API comparison
17 vendors. Click headers to sort.
| Vendor | Category | Free tier | Lowest paid $/mo | History (yrs) | Asset classes | Real-time | WebSocket | Rate limits |
|---|---|---|---|---|---|---|---|---|
| Massive (formerly Polygon) | market-data | yes | $29 | 20+ | us-stocks, options, indices, forex, futures | real-time on Stocks Advanced; 15-min delayed on Starter/Developer | yes (Starter and up) | Free: 5 calls/min; paid: unlimited |
| Databento | market-data | yes | Pay-as-you-go ($/GB); $125 free credits | 16+ | futures, options, us-stocks | live data on subscription plans | Raw TCP + client libraries (live streaming) | Unlimited downloads, streaming and API calls on subscriptions |
| Alpaca | broker+data | yes | $99 | 7+ | us-stocks, options, crypto | Free: IEX real-time websocket; Plus: all US exchanges | yes | Free: 200 calls/min; Algo Trader Plus: unlimited |
| Tiingo | market-data | yes | $30 | 30+ | us-stocks, china-stocks, etfs, mutual-funds, crypto | IEX feed (real-time row present, details unclear) | unknown | Free: 50 req/hr, 1,000/day, 500 symbols/mo, 1 GB/mo; Power: 10,000/hr, 100,000/day, 40 GB/mo |
| Financial Modeling Prep | market-data | yes | $29 | 30+ | stocks, fundamentals, etfs | unknown | unknown | 250/day free; 300, 750, 3,000/min paid; 30-day bandwidth caps 500MB/20GB/50GB/150GB |
| EODHD | market-data | yes | $19.99 | 30+ | global-stocks, etfs, forex, crypto, indices, commodities, fundamentals | Live/delayed (free: 15-min) | yes (Intraday & ALL-IN-ONE: 50 tickers) | Free: 20/day, 20/min; paid: 100,000/day, 1,000/min |
| Alpha Vantage | market-data | yes | $49.99 | 25+ | stocks, etfs, mutual-funds, options, forex, crypto, commodities, economic | Real-time and 15-min delayed US data on premium (entitlement required) | unknown | Free 25/day; premium 75-1200/min, no daily limits |
| Finnhub | market-data | yes | $49.99 | 40+ | us-stocks, fundamentals, etfs, forex, crypto, bonds, economic | unknown | yes (Free 50 symbols; Basic 250; Standard/Pro unlimited) | Free 60 calls/min; All-In-One 900/min market data, 300/min fundamentals |
| ThetaData | market-data | unknown | $40 | 14+ | options, stocks, indices, interest-rates | real-time | streaming (Pro) | Concurrent-request limits: 2/4/8 |
| Twelve Data | market-data | yes | $29 | unknown | stocks, etfs, forex, crypto, commodities, bonds, mutual-funds | Real-time US stocks (Grow+), real-time forex/crypto | yes (WS credits; trial on Basic/Grow) | API credits per minute: 8 (free) up to 10,946 |
| Intrinio | market-data | unknown | $150 | 50+ | us-stocks, options, fundamentals, etfs | Real-time (EquitiesEdge/OptionsEdge) and 15-min delayed | yes (WebSocket on some feeds) | unknown |
| IBKR API (Interactive Brokers) | broker | unknown | $1.5 | unknown | stocks, options, futures, forex, bonds, funds, prediction-markets | real-time with subscriptions | unknown | unknown |
| Tradier | broker | yes | $10 | unknown | stocks, options, futures | unknown | unknown | unknown |
| Tradovate | broker | yes | $99 | unknown | futures, event-contracts | Top of book data with funded account | unknown | unknown |
| SEC EDGAR (free) | public-data | yes | unknown | unknown | filings, fundamentals-xbrl | real-time as filings are disseminated | no | Must comply with SEC fair-access policy (see Developer FAQs) |
| Kalshi API | prediction-market | unknown | unknown | unknown | prediction-markets | unknown | yes (user fills websocket channel referenced) | Token buckets per tier (Basic, Advanced, Premier, higher); default cost 10 tokens/request; separate Read and Write budgets. Example: Premier Write refills 1,200 tokens/s (≈120 orders/s), capacity 3,600. Balance endpoint 1/s (Basic/Advanced) or 5/s (higher). Basic/Advanced per-second budgets not captured. |
| Polymarket API | prediction-market | unknown | unknown | unknown | prediction-markets | unknown | yes (Market/User/Sports channels) | IP-based (Cloudflare), sliding windows: general 15,000 req/10s; Gamma API 4,000/10s; Data API v1 1,000/10s; CLOB 9,000/10s (/book 1,500/10s); POST /order burst 5,000/10s, sustained 120,000/10min |