Search "financial data API" and you'll get a wall of vendors that all sound roughly the same: real-time prices, financial statements, some SEC data, an API key, and a pricing page. They're not the same. Some are built to stream market prices to a trading desk; some are built to hand an AI agent structured, cited disclosure data it can reason over. Picking wrong means re-architecting later, so here's what five named providers actually cover, what they cost, and where FocusAlpha sits among them, based on each vendor's own published pricing and documentation as of July 2026.
TLDR:
- The five providers split into two real categories: market-data-first (prices, quotes, streaming) versus fundamentals/disclosure-first (filings, financials, transcripts) — and conflating them is the single most common evaluation mistake.
- Pricing spans an order of magnitude, from a $20 one-time credit pack to several-thousand-dollar enterprise plans, and the billing unit differs as much as the price: per-request, per-bandwidth, and per-verified-answer are three different bets on what you'll actually consume.
- Only some of these providers were built agent-first from the ground up; the rest bolted MCP or LLM-friendly docs onto a pipeline originally designed for spreadsheets and terminals.
What each provider actually covers
| Provider | Primary focus | Coverage | Starting price |
|---|---|---|---|
| financialdatasets.ai | US fundamentals & filings for LLMs/agents | 27,000+ tickers, US equities only | $20 one-time (1K requests) / $200/mo |
| Financial Modeling Prep | Broad market + fundamentals | 70,000+ securities, 46 countries | Free (250 req/day) / ~$14-15/mo |
| Massive (formerly Polygon.io) | Real-time & historical market data | US market data; rebranded Oct 2025 | Free (5 calls/min) / $29/mo |
| EODHD | Global market + fundamentals + alt data | 150,000+ tickers, 60+ exchanges | $19.99/mo (personal) |
| FocusAlpha | Disclosure + fundamentals, agent-native, cited | 5,000+ US + Japan/Taiwan/Korea/HK/ADR | $39/mo (credit-based) |
Sources: financialdatasets.ai/pricing; site.financialmodelingprep.com/pricing-plans; massive.com/blog/polygon-is-now-massive; eodhd.com/pricing; focusalpha.ai/pricing. As of July 2026.
The starting prices aren't comparable on their own — they're not metering the same thing. EODHD and Massive charge for request volume against mostly market/price data. Financial Modeling Prep charges against bandwidth and endpoint tier across the broadest raw security count of the group. FocusAlpha charges per verified research answer rather than per raw API call — a credit only gets spent when the platform returns something usable, not every time an agent pings an endpoint mid-reasoning-loop.
Figure 1: Raw ticker count isn't the whole story — FocusAlpha's smaller number reflects curated coverage of companies above $5B market cap plus multi-channel depth per company, not a smaller net. Source: each provider's published pricing and coverage pages, July 2026. See Table 1.
Two categories, not one
The label "financial data API" covers two genuinely different products, and most buyer's-guide content flattens them into one list. Splitting them is the fastest way to rule out three of these five providers for any given use case.
| Provider | Market data (prices, quotes, streaming) | Fundamentals & financials | Disclosure documents (filings, transcripts) | Built agent-first |
|---|---|---|---|---|
| financialdatasets.ai | Limited | Yes | SEC filings | Yes — explicit LLM/agent positioning, MCP server |
| Financial Modeling Prep | Yes | Yes | Limited | No — REST/WebSocket/bulk, dev-first not agent-first |
| Massive (formerly Polygon.io) | Yes — core product | No | No | No — trading/quant infrastructure heritage |
| EODHD | Yes | Yes | Limited (Form 4, institutional holdings) | No — broad generalist, not agent-specific |
| FocusAlpha | No | Yes | Yes — filings, transcripts, IR content, multi-channel | Yes — API + MCP, citations by construction |
Sources: same as above, cross-referenced against each provider's own product/feature pages, July 2026.
Figure 2: Where each provider sits — most of the field clusters toward market data or a generalist middle; agent-native disclosure data is a comparatively empty quadrant. Source: each provider's published product and pricing pages, July 2026.
Massive sits alone in market-data-only: it's real-time price infrastructure, not a fundamentals or filings product, and comparing it to the other four on "coverage of SEC filings" isn't a fair fight; it was never built for that. Financial Modeling Prep and EODHD are the broadest generalists, spanning both categories at meaningful depth, which is exactly why they're priced and positioned as all-purpose data platforms rather than specialists. financialdatasets.ai and FocusAlpha are the two actually built for agent consumption from the start, and even between those two the split is real: financialdatasets.ai is US-only and structured around raw endpoint access, while FocusAlpha adds cross-market coverage and multi-channel context (earnings calls, IR content, leadership interviews) with citations attached to every value.
What to actually test before choosing
None of the marketing pages above answer the question that matters for an agent build: does the data hold up at the field level, not just the ticker-count level. A vendor listing "150,000+ tickers" says nothing about how complete any single company's record is.
| Evaluation question | Why it matters |
|---|---|
| What fraction of fields is populated for a mid-cap company, not just an S&P 500 name? | Headline ticker counts don't reveal per-field completeness — coverage gaps concentrate outside large caps. |
| Does the API expose non-US markets, or is "global" limited to US ADRs? | Three of the five providers reviewed here are functionally US-only despite broader marketing language. |
| Is pricing metered on raw requests or on usable answers? | A per-request model charges the same whether an agent's query succeeds or fails; a per-answer model doesn't. |
| Is there a native MCP server, or only a REST API with LLM-friendly docs? | Agent-first design changes how much integration work your team does versus the vendor. |
Source: evaluation framework derived from the coverage and pricing data above, July 2026.
Where FocusAlpha fits
FocusAlpha isn't trying to be the sixth generalist on this list — it's not a market-data provider, and it doesn't try to out-cover Financial Modeling Prep or EODHD on raw ticker count. It's built for the narrower, deeper job: complete, cited, agent-ready disclosure and fundamentals data — SEC filings, earnings-call transcripts, financials, IR content, and leadership commentary — across the US plus Japan, Taiwan, Korea, Hong Kong, and ADRs, billed for verified answers rather than raw request volume. Agents reach that disclosure layer through a single SEC filings API where every value carries its citation back to the source document. (For why that citation layer matters for agents, see why AI agents need a trusted data layer.)
FAQ
What's the difference between a market data API and a fundamentals/disclosure data API?
A market data API (like Massive) provides prices, quotes, and trading-related data, often real-time via streaming. A fundamentals/disclosure API (like FocusAlpha or, more narrowly, financialdatasets.ai) provides financial statements, SEC filings, and related company documents. Many providers, like Financial Modeling Prep and EODHD, offer both, but at different depths.
Which financial data API is best for AI agents?
Of the five reviewed here, financialdatasets.ai and FocusAlpha are explicitly built for agent consumption — with MCP servers and structured, LLM-friendly output — versus the others, which expose REST APIs originally designed for traditional software integration. FocusAlpha additionally adds citation-by-construction and cross-market coverage beyond the US.
How much does a financial data API cost in 2026?
Starting prices range from a $20 one-time credit pack (financialdatasets.ai) to free tiers with rate limits (Financial Modeling Prep, Massive) to $19.99-$39/month entry paid tiers (EODHD, FocusAlpha). Enterprise/commercial tiers run from a few hundred to several thousand dollars per month depending on volume and data scope.
Does any of these providers cover non-US markets well?
EODHD has the broadest raw non-US coverage (60+ exchanges, 150,000+ tickers, though only 15-20 years of history outside the US). Financial Modeling Prep covers 46 countries. financialdatasets.ai and Massive are functionally US-only. FocusAlpha covers the US plus Japan, Taiwan, Korea, Hong Kong, and ADRs for companies above $5B market cap, focused on disclosure/fundamentals rather than raw market data.
What happened to Polygon.io?
Polygon.io rebranded to Massive on October 30, 2025. Existing APIs, accounts, and integrations continued working under the new name; api.polygon.io remained supported for a transition period alongside the new api.massive.com endpoint.
Should I pick one financial data API or combine several?
Because no single provider here spans both categories at full depth while also being agent-native, most agent builds combine at least two: a market-data provider (like Massive) for prices, and a fundamentals/disclosure provider (like FocusAlpha) for filings and financials.
What is FocusAlpha?
FocusAlpha is a SEC filings API and agent-ready financial data layer: it turns SEC filings (10-K, 10-Q, 8-K, 13F), earnings-call transcripts, and other trusted company communications into structured, normalized data where every value keeps its citation back to the source document. AI agents connect via API or MCP to research public companies from complete, trusted information.