The short answer

Polygon.io is now Massive: the rebrand went official on October 30, 2025, and polygon.io redirects to massive.com. Among the three, Massive sells flat-rate plans with unlimited API calls from $29/mo, Tiingo caps calls per hour plus bandwidth but keeps the simplest commercial license at $50/mo, and Finnhub's 60-calls/min free tier is the strongest $0 entry — personal use only.

First, the name: Polygon.io is now Massive. The rebrand went official on October 30, 2025, and polygon.io 301-redirects to massive.com: same API, same tiers, new name. With that settled, the three-way split is clean: Massive sells flat-rate plans with unlimited API calls from $29/mo, Tiingo caps calls per hour plus bandwidth but keeps the simplest commercial license in the field at $50/mo, and Finnhub has the strongest $0 entry (60 calls/min, real-time US quotes, a WebSocket) that turns personal-use-only the moment revenue is involved. For most workloads the deciding factors are rate-limit architecture and licensing, not list price. The Data Vendor TCO calculator does the annual math for your scenario.

What happened to Polygon.io?

If you searched "polygon" and landed here: Polygon.io rebranded to Massive on 2025-10-30, and polygon.io now redirects to massive.com. Nothing about the data products was discontinued in the rename, and 2026 has been expansionary: a Futures product line launched 2026-05-28 (CME, CBOT, NYMEX, COMEX), an SEC Filings & Disclosures product on 2026-03-06, and new splits/dividends endpoints in February. Everything in this comparison uses the Massive name, with prices re-read from massive.com/pricing and massive.com/business on 2026-10-11. The tier-by-tier breakdown lives in Polygon.io Pricing Plans 2026.

A note on method: all three vendors render pricing with JavaScript, so the figures below were extracted from each page's own embedded plan data (and cross-checked against the vendors' app bundles), not from third-party summaries. Massive, Tiingo and Finnhub were all re-read on 2026-10-11.

How do Tiingo, Massive, and Finnhub compare in 2026?

Dimension Tiingo Massive (ex-Polygon.io) Finnhub
Free tier $0: 50 req/hr, 1,000/day, 500 unique symbols/mo, EOD 30+ yrs, IEX feed, news Basic $0 per asset class: 5 calls/min, EOD only, 2 yrs history $0: 60 calls/min, real-time US quotes, WebSocket (50 symbols), no historical OHLC
Entry paid Power $30/mo ($300/yr) Stocks Starter $29/mo (15-min delayed) Market Data Basic $49.99/mo (billed quarterly)
Real-time tier IEX-sourced real-time on all plans Stocks Advanced $199/mo (full SIP) Real-time US /quote on free; WS "US Full SIP" on Market Data plans
Rate limits (paid) Power 10,000/hr + 40 GB/mo; Commercial 20,000/hr + 100 GB/mo "Unlimited API calls" on all paid tiers 150–900/min by plan, global hard cap 30 calls/sec
WebSocket Firehose on every plan including free (IEX, FX, crypto) None on free; Starter aggregates, Developer adds trades, Advanced adds quotes One socket; 50 → 250 → unlimited symbols by plan
Flat files / bulk None published S3 flat files from Starter (trades from Developer, quotes on Advanced) Pricing table lists 30+ years of OHLC and tick history on its top plans
Options No Separate Options product ($29–$199/mo) Not verifiable from the pricing page
Commercial license $50/mo ($499/yr), internal use, ≤2 devs Stocks Business $2,499/mo Written approval required; redistribution is Enterprise-only

Prices are list rates from the vendors' pages, re-read on 2026-10-11. The wider six-vendor field (Databento, FMP, Alpha Vantage included) is covered in Market Data APIs Compared 2026, and Cheapest Stock Market Data API 2026 ranks the lowest-cost paths.

Which rate-limit architecture fits your workload?

The three vendors meter access in structurally different ways, and for a quant workload this matters more than a few dollars of list price:

  • Massive: unlimited calls. No quota on any paid tier. "Unlimited" means no metered ceiling (throughput is still bounded by your HTTP connections), so a 10,000-symbol backfill is an engineering problem, not a billing one.
  • Tiingo: hourly buckets plus bandwidth. Power allows 10,000 requests/hr, 100k/day, and 40 GB/mo. The bandwidth cap is the one that bites: a full-universe minute-bar backfill can exhaust 40 GB long before it exhausts the request budget. Batch your pulls and cache aggressively.
  • Finnhub: per-minute plus a global ceiling. Paid plans meter 150–900 calls/min, and every plan shares a hard 30 calls/sec cap. Fine for live polling of a modest universe; slow for bulk history via REST.

Rule of thumb: bulk backfills favor Massive (S3 flat files from the $29 Starter tier); steady polling of a small universe fits any of the three; bandwidth-heavy REST scraping is Tiingo's weak spot despite generous request counts.

Who can legally use which plan?

Licensing is where the real prices hide, and the three read very differently:

  • Tiingo is the simplest: standard plans are internal-use only, and the Commercial plan at $50/mo ($499/yr) covers internal commercial use for up to two developers. Redistribution needs a sales conversation, but a solo quant running a revenue-generating strategy is cleanly covered for $50.
  • Massive is the most explicit: individual plans are personal-use, the Advanced tiers require a non-professional qualification, and commercial use means Stocks Business at $2,499/mo, sold with "No Exchange Fees or Approvals" on its fair-market-value feed. Exchange-feed expansions ($399–$1,999/mo plus exchange fees) sit on top for firms that need them.
  • Finnhub looks cheap until this row: every self-serve plan is personal-use, commercial or professional use requires written approval, and redistribution is Enterprise-only. The 60-calls/min free tier is excellent for learning. It is not a production license.

If "can I legally run this in a paid product" is your question, Tiingo's $50/mo answer is the shortest path among the three. For the EU-specific licensing and record-keeping overhead, see Data Vendor TCO for EU Retail.

Where do real-time, WebSockets, and history depth differ?

  • Real-time: Tiingo serves IEX-sourced real-time on every plan, including free; IEX is one exchange, not the consolidated tape. Massive gates full real-time behind Stocks Advanced ($199/mo); Starter and Developer are 15-minute delayed. Finnhub's /quote is real-time US on every plan and its WebSocket is labeled US Full SIP, with LSE 15-minute delayed and most other international coverage EOD unless you go Enterprise.
  • WebSockets: Tiingo is the outlier: firehose sockets for IEX equities, forex, and crypto on all plans including free. Massive has no socket on free and adds aggregates, then trades, then quotes as you climb tiers. Finnhub caps socket symbols (50 free / 250 Basic / unlimited from Standard).
  • History depth: Finnhub's pricing table lists 30+ years of OHLC and tick history on its top plans. Tiingo carries 30+ years of EOD on every tier including free. Massive steps from 2 years (Basic) to 5, 10 and 20+ years across Starter, Developer and Advanced.
  • Sourcing: Massive builds from the SIPs plus direct exchange connections and FINRA TRFs; Tiingo's IEX feed comes from raw binary feeds processed near NY5; Finnhub's US socket is labeled Full SIP with forex from FXCM and Forex.com.

Which vendor is AI-agent ready?

A 2026-specific dimension: if your research stack runs through MCP or LLM agents, the three are not equal. Massive shipped an llms.txt on 2026-01-22, rebuilt its official MCP server on 2026-03-30, launched a hosted OAuth MCP server at mcp.massive.com on 2026-09-15, and began selling per-request stock data to agents over x402 on 2026-09-01 (Massive for AI Agents 2026). It grades A in our Finance MCP Directory. Finnhub documents an AI copilot endpoint in its API docs but ships no official MCP server. Tiingo publishes neither an llms.txt nor an MCP server; community wrappers exist with varying quality. For agent-driven workflows, Massive is currently the only one of the three treating machine consumers as first-class.

What changed in 2026?

Honest freshness, per vendor:

  • Massive: an active year — ETF Global partnership (Jan 7), llms.txt (Jan 22), splits/dividends endpoints (Feb 18), SEC Filings & Disclosures (Mar 6), Labor Market API (Mar 23), rebuilt MCP server (Mar 30), Futures launch (May 28), LULD WebSocket channel (Jun 18), x402 per-request access for agents (Sep 1), hosted MCP server (Sep 15). All from massive.com/blog. Its business page lists Stocks Business at $2,499/mo; an earlier version of this page gave $1,999, which is the Options Business price.
  • Tiingo: no dated 2026 changes found on its site. Pricing re-verified 2026-10-11: unchanged since July.
  • Finnhub: publishes no official changelog, so 2026 changes cannot be verified from the source. Prices above are what its pricing page served on 2026-10-11, unchanged since July.

Decision guidance

  • Learning, prototyping, personal dashboards at $0: Finnhub free (60 calls/min, real-time US quotes, WebSocket), mind the personal-use restriction. Details in Is Finnhub Free? 2026.
  • Long-horizon EOD research on a budget: Tiingo — free Starter for 500 symbols/mo, Power at $30/mo for the full universe.
  • A revenue-generating solo product on a budget: Tiingo Commercial at $50/mo; the cheapest clean commercial license here by a wide margin.
  • Flat-rate intraday with no per-call accounting: Massive Stocks Starter $29/mo (15-min delayed) or Advanced $199/mo (real-time SIP).
  • Bulk historical tick data: Massive's S3 flat files (trades from the $79 Developer tier; see Massive Flat Files 2026); for institutional-grade L2, step up to Databento vs Polygon.io 2026.
  • Agent/MCP-driven stacks: Massive, on llms.txt + official MCP server.

Run your own universe, resolution, and licensing scenario through the Data Vendor TCO calculator before subscribing: the cheapest vendor flips with the workload.

Sources

Editorial independence

AI Fin Hub Research maintains editorial independence across sponsor relationships. Vendor placements in tools and comparators are not altered by sponsor payments. Disclosures at /sponsor-disclosure/.

Frequently asked questions

Did Polygon.io change its name?
Yes. Polygon.io rebranded to Massive on October 30, 2025, and polygon.io now 301-redirects to massive.com. The API and tier structure carried over (Stocks: free Basic, $29 Starter, $79 Developer, $199 Advanced), and 2026 brought additions rather than cuts: a Futures product line in May, an SEC Filings & Disclosures product in March, a rebuilt MCP server in March, and a hosted MCP server plus x402 agent access in September. Re-verified against massive.com on 2026-10-11.
Tiingo vs Polygon (Massive): which is cheaper for a solo quant?
List prices are nearly identical at entry ($30/mo Tiingo Power vs $29/mo Massive Stocks Starter, re-verified 2026-10-11) but the architectures differ: Tiingo meters 10,000 requests/hr plus a 40 GB/mo bandwidth cap and serves IEX-sourced real-time on every plan, while Massive's Starter has unlimited API calls but is 15-minute delayed, with full-SIP real-time costing $199/mo on Advanced. For commercial use the gap widens sharply: Tiingo's commercial license is $50/mo; Massive's Stocks Business tier is $2,499/mo.
Is Finnhub free for commercial use?
No. Finnhub's free tier (60 calls/min, real-time US quotes, a 50-symbol WebSocket) and all self-serve paid plans are personal-use; commercial or professional use requires written approval from Finnhub, and redistribution is Enterprise-only. Budget for that conversation, or for a vendor with self-serve commercial licensing like Tiingo ($50/mo), before shipping a paid product on Finnhub data.
Which market data API works best with AI agents in 2026?
Massive (formerly Polygon.io) is furthest ahead of these three: it shipped an llms.txt in January 2026, rebuilt its official MCP server in March 2026, launched a hosted OAuth MCP server in September 2026, and grades A in our Finance MCP Directory. Finnhub documents an AI copilot endpoint but has no official MCP server; Tiingo ships neither an llms.txt nor an MCP server, leaving only community wrappers.