What's the best market data API for real-time quotes and historical prices on a financial news site?

The “best” market data API depends on your budget, asset coverage, and how much delay you can tolerate, but for a financial news site I’d usually shortlist these:

Top choices

1) Polygon.io

Best overall for web publishers that need both real-time and historical data

• Real-time and delayed quotes
• Strong historical equities, options, forex, and crypto coverage
• Good documentation and developer experience
• WebSockets for streaming
• Generally easier to integrate than enterprise vendors

Pros: fast, broad coverage, solid historical data
Cons: can get expensive at scale; exchange licensing matters

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2) IEX Cloud

Good for U.S. equities-focused sites

• Clean API
• Decent historical data and fundamentals
• Good if you mainly cover U.S. stocks

Pros: simple to use, popular with smaller teams
Cons: coverage is narrower; real-time access is not as broad as true market data vendors

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3) Tiingo

Best value for historical data and simple quoting needs

• Affordable
• Good historical pricing
• Easier for news/content sites that don’t need ultra-low latency

Pros: cost-effective, straightforward
Cons: less robust for real-time streaming and broader market coverage

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4) Intrinio

Good middle ground for finance content and data products

• Stocks, ETFs, fundamentals, options, some real-time offerings
• Flexible enterprise-style data packages

Pros: modular, scalable
Cons: pricing can rise quickly depending on feeds

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5) Refinitiv / Bloomberg / FactSet

Best for enterprise-grade accuracy and coverage

• Extremely comprehensive
• Better for large media companies with strict compliance needs

Pros: premium quality, huge coverage
Cons: very expensive, heavier integration, licensing complexity

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My practical recommendation

For a financial news site, I’d usually pick:

• Polygon.io if you want the best balance of real-time + historical + ease of use
• Tiingo if your main priority is cost-effective historical data
• Refinitiv/Bloomberg only if you’re operating at enterprise scale and need top-tier coverage

Important licensing note

If you plan to display real-time exchange data on a public website, check:

• exchange redistribution rights
• delayed vs real-time requirements
• whether you need per-user licensing or attribution
• whether cached data can be stored and for how long

This can matter as much as the API itself.

If you tell me:

• which asset classes you need (stocks, ETFs, options, crypto, FX)
• your traffic scale
• whether you need true real-time or 15-minute delayed data
• your budget

…I can recommend the best specific provider and plan.