Overview
Polygon.io is a comprehensive market data API providing real-time and historical stock, forex, and cryptocurrency data. You can retrieve OHLCV price bars, live quotes, trade data, and company fundamentals for thousands of tickers. It is a popular choice for developers building trading algorithms, financial dashboards, and quantitative research tools.
Beginner Tip
The free tier provides access to previous-day data with a 15-minute delay; upgrade to a paid plan for real-time streaming or intraday data if your app requires live prices.
Available Data
Example Response
{
"base": "USD",
"date": "2025-01-15",
"rates": {
"EUR": 0.92,
"GBP": 0.79,
"JPY": 149.5,
"CAD": 1.35
}
} Field Reference
ticker The stock ticker symbol for the requested security. results Array of OHLCV bar objects for the requested time range. o Opening price of the security for the given time interval. h Highest price reached during the time interval. c Closing price of the security at the end of the time interval. v Total trading volume (number of shares) during the time interval. Implementation Example
// Get daily stock aggregates (OHLCV)
const url = "https://api.polygon.io/v2/aggs/ticker/AAPL/range/1/day/2023-01-09/2023-01-10?apiKey=YOUR_API_KEY";
const response = await fetch(url);
if (!response.ok) throw new Error(`Request failed: ${response.status}`);
const data = await response.json();
console.log(`Symbol: ${data.ticker}`);
console.log(`Results count: ${data.resultsCount}`);
data.results.forEach(bar => {
console.log(`Date: ${new Date(bar.t)}, Open: $${bar.o}, High: $${bar.h}, Low: $${bar.l}, Close: $${bar.c}, Volume: ${bar.v}`);
}); What Can You Build?
Note: These code examples are AI-generated and unverified. Always refer to the official API documentation for accurate usage.
Common Errors & Troubleshooting
Matrix Score Breakdown
Partially tested on Apr 5, 2026
Technical Specifications
Alternatives to Polygon
Technical alternatives for different use cases.
Real-time and historical market data with WebSocket
Free tier availability and pricing
Institutional-grade market data with low latency
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