# Finnhub vs Massive (formerly Polygon.io) (slim)

> Massive scores 73.1 (BB) to Finnhub's 45.1 (E) for market prices. Prices, MCP, x402, uptime and agent notes side by side.

- Full: https://www.anchorterminal.com/compare/finnhub-vs-massive.md (~4,600 tokens) · this version ~2,830 tokens · JSON https://www.anchorterminal.com/compare/finnhub-vs-massive.json · canonical https://www.anchorterminal.com/compare/finnhub-vs-massive
- Index: https://www.anchorterminal.com/llms.txt · API: https://www.anchorterminal.com/api/v1/index.json · MCP: https://www.anchorterminal.com/mcp · Updated: 2026-11-03
- Licence: CC BY 4.0, credit Anchor Terminal and link this page (https://www.anchorterminal.com/terms/#data)

Massive (formerly Polygon.io) scores 73.1 (BB) on agent readiness against Finnhub's 45.1 (E), and leads in every scored category. Both do market prices. Massive (formerly Polygon.io) accepts x402. Finnhub doesn't.

- Finnhub: E 45.1, rank #1140 of 1349 · https://www.anchorterminal.com/tools/finnhub.min.md
- Massive (formerly Polygon.io): BB 73.1, rank #100 of 1349 · https://www.anchorterminal.com/tools/massive.min.md
- Finnhub, good for Agents that need one key across quotes, fundamentals, estimates, filings and transcripts with official libraries, and a free key for prototypes. Also Free to start without a card.
- Massive (formerly Polygon.io), good for Agents that need US equities, options or futures data with real history, and the only listing here selling US stock data over x402. Ahead on Reliability, 78 against 48; Schema & documentation, 89 against 58; Agent ergonomics, 78 against 56; Payments & pricing, 90 against 30; Maintenance & community, 82 against 60; Transparency & trust, 67 against 27. Also Agent-ready, a grade of BB or better; An agent can pay per call over x402, with no account.

| Category | Finnhub | Massive (formerly Polygon.io) |
| --- | --- | --- |
| Reliability (16%) | 48 | 78 |
| Performance (10%) | pending | pending |
| Schema & documentation (13%) | 58 | 89 |
| Agent ergonomics (13%) | 56 | 78 |
| Security & auth (14%) | 32 | 35 |
| Payments & pricing (10%) | 30 | 90 |
| Task success (10%) | pending | pending |
| Maintenance & community (7%) | 60 | 82 |
| Transparency & trust (7%) | 27 | 67 |

| Fact (where they differ) | Finnhub | Massive (formerly Polygon.io) |
| --- | --- | --- |
| Vendor | Finnhub | Massive |
| Hosted endpoint | `https://finnhub.io/api/v1` | `https://api.massive.com` |
| Transports | HTTP, Streamable HTTP, websocket | HTTP, Streamable HTTP |
| Auth | OAuth or key | API key |
| x402 | no | yes, from $0.01/call |
| Licence | none | MIT (clients) |
| Tools exposed | 70 | none |
| llms.txt | no | yes |
| Last release | 2026-11-02 | 2026-10-28 |
| Terms last updated | couldn't be read | 2026-10-06 |
| Privacy policy last updated | no document linked | 2024-03-22 |
| Customer content may train models | couldn't be read | not found in the text |
| Terms restrict automated access | couldn't be read | yes |
| Terms restrict benchmarking | couldn't be read | yes |
| Terms or service can change without notice | couldn't be read | not found in the text |
| Arbitration or class-action waiver | couldn't be read | yes |
| Popularity | 1.1k stars | 1.5k stars |
| Agent reviews | none | 3.5/5 (2) |

Why the edge:
- Payments & pricing, Massive (formerly Polygon.io) +60: Finnhub 30 (No x402, MPP or L402 (0). Plan prices are public without login, read from the pricing page's script data, sold per dataset by the month with calls a minute rather than per call (10). A free key at 60 calls a minute with no card, which the pricing FAQ says can be used forever (20). The key comes from a browser signup and no key API was found (0). 0 + 10 + 20 + 0 = 30.); Massive (formerly Polygon.io) 90 (x402 on its own domain at agent.massive.com since 1 September, but only 23 US stock routes. Options, indices, forex, crypto, futures, tick data and streaming still need a key (30 of 40). $0.01 a route on Agentic.Market, which the docs link to, and plan prices on massive.com/pricing, all without a login (20). Free Basic plan at 5 calls a minute with end-of-day data. The pricing page doesn't say a card is needed (20). An agent with a funded Base wallet can pay with no account (20).)
- Transparency & trust, Massive (formerly Polygon.io) +40: Finnhub 27 (A closed service whose terms exist at a page that robots.txt disallows, so they were not read; the pricing page says every self-serve plan is personal use, and no legal entity or governing law was found (8 of 30). No privacy policy was found, /privacy redirecting to the home page (0 of 30). No deprecation policy or dated notices found (0 of 20). Stripe and Braintree scripts load on the site, but no processor list or data location is disclosed (0 of 20). 8 + 0 + 0 + 0 = 8.); Massive (formerly Polygon.io) 67 (Closed service under business terms last updated 6 October 2026, Massive.com, Inc. under Georgia law, which now also cover pay-per-request purchases without an account. The MCP server and clients are MIT (15). Privacy policy last updated 22 March 2024, with retention 'as long as we are providing the Services' and no periods. The business terms require deleting data on termination. No DPA found (12 of 30). Dated sunsets in the changelog. The terms let Massive change the Services at its discretion, with a 30-day route to report a change that materially degrades a subscribed service (10 of 20). Stripe, Google and Hotjar are named, and data may sit 'in the United States and locations around the world'. No subprocessor list (8 of 20).)
- Schema & documentation, Massive (formerly Polygon.io) +31: Finnhub 58 (A public Swagger 2.0 document covers 116 paths with a description on every operation, declaring the key as a query parameter and a 200 response only; the MCP tools were not read (20 of 25). /llms.txt returns the site's HTML shell and no Markdown docs exist (0 of 10). Each operation states its purpose, a premium marker and, on quote, advice against polling, with little on when not to use it (14 of 20). Required flags and types are set on 248 parameters, but allowed values such as news categories sit in description text and no enum is declared (8 of 15). Every operation has example URLs and sample code in five languages, while the only documented error is the 429 (9 of 15). The path carries v1 and no changelog or dated change notes were found (7 of 15). 20 + 0 + 14 + 8 + 9 + 7 = 58.); Massive (formerly Polygon.io) 89 (OpenAPI document at api.massive.com/openapi (OpenAPI 3.0.3, 148 paths) with enums such as `timespan` and `sort`, and 400, 401 and 404 responses defined (25). llms.txt at massive.com/docs/rest/llms.txt indexing about 160 endpoint pages (10). One-line descriptions per endpoint in the index, longer ones in the reference, with little on when not to use a call (14 of 20). Typed path and query parameters with enums and required fields (13 of 15). Examples in the docs and error responses in the spec, though the llms.txt says nothing about error shapes (12 of 15). Versioned paths from /v1 to /v3 and a dated public changelog (15).)
- Reliability, Massive (formerly Polygon.io) +30: Finnhub 48 (Read with the hosted lines. No status page was found on the site, in the docs document or on the MCP page (0), so no incident history could be read (5). Limits are published with numbers, 60 calls a minute on the free key, 150 to 900 a minute by plan, and 30 calls a second on top of every plan (15). The docs say the limit answers 429 and the MCP page says to wait a minute, with no Retry-After or backoff guidance (8 of 15). The home page says 99.99 per cent uptime with an SLA available for enterprise clients (10). The API is generally available (10). 0 + 5 + 15 + 8 + 10 + 10 = 48.); Massive (formerly Polygon.io) 78 (Atlassian Statuspage at massive-status.com with REST, WebSocket and flat-file components for each asset class (20). The history feed lists 14 unplanned incidents from 3 August to 1 November 2026, each limited to one product, one endpoint, one asset class or some accounts. They include US equity aggregate bars missing for roughly two-thirds of US equities from 18:46 ET on 8 September until 10:29 the next day, stale stocks quotes on 20 August, and slow responses with intermittent 502s on stocks v2 aggregates from 10:37 to 13:08 ET on 2 September. The newest, on 27 October, was delayed WebSocket data and REST errors for some accounts from 13:49 to 14:17 EDT. Read the way partial incidents are read on other listings, that is minor incidents only (20). Free plan limited to 5 calls a minute, paid plans unlimited, nothing stated for x402 (10 of 15). No 429 or Retry-After guidance found in the docs or the OpenAPI file, though the official Python client retries 429 with backoff (8 of 15). The business terms dated 6 October 2026 point to a separate Support Policy and SLA document for customers who buy service levels (10). The REST API is generally available (10).)
- Agent ergonomics, Massive (formerly Polygon.io) +22: Finnhub 56 (The REST API is the surface graded. `from` and `to` on candles and news, and symbol-scoped calls, size responses; no field selection, and the MCP server lists 70 tools (12 of 25). Date filters but no pagination on most lists (10 of 20). Only the 429 is documented; a missing key answered 401 with a JSON `error` field in our one test call (5 of 20). All but one operation are GET reads; the MCP annotations were not read (14 of 20). Few required parameters and official libraries in six languages (15). 12 + 10 + 5 + 14 + 15 = 56.); Massive (formerly Polygon.io) 78 (`limit`, `sort` and `adjusted` on most list and aggregate calls, no field selection found (15 of 25). `next_url` pagination that the official clients follow for you, plus date and ticker filters (18 of 20). Errors in the spec carry a status and message, with 400 responses on 64 of the 148 operations (14 of 20). All market data calls are GETs, and the x402 docs say only successful requests are charged and each page is charged separately. The hosted MCP's three tools carry readOnlyHint, per the 1 October check (16 of 20). Official clients in Python, JavaScript, Go and the JVM, with few required parameters (15).)
- Maintenance & community, Massive (formerly Polygon.io) +22: Finnhub 60 (Read as a closed service. The newest dated change is 2 November 2026, when finnhub-go, finnhub-ruby and finnhub-php gained a price target history endpoint; the MCP page is dated 6 August 2026 (30). Only that one dated change falls in the last 90 days, the previous library commits being 22 June 2026 (5 of 20). Support by email, with no public changelog or community channel found (5 of 15). Six official client libraries, finnhub-python at 2.4.29 of 24 June 2026 (15). The libraries are generated from the API document; no CI run was visible and the Python README names an older version than PyPI (5 of 10). 30 + 5 + 5 + 15 + 5 = 60.); Massive (formerly Polygon.io) 82 (Newest changelog entry 2026-10-28, new Insider Trading Activity and Insider Holdings endpoints (30). Changelog entries on 25 August, 1 September, 22 September, 2 October, 16 October and 28 October, six in 90 days, besides client releases (20). Public changelog and a support channel. We couldn't read GitHub issue activity in this run (10 of 15). Official clients are current, with Python v2.9.0 on 2026-10-16 and v2.9.1 on 2026-10-25, Go v3.5.0, v3.6.0 and v3.7.0 between 20 and 27 October and JavaScript v10.8.0 on 2026-09-17, each regenerated from the OpenAPI spec (15). The MCP and client repos run CI. The MCP server repository is still at v0.10.0 of 2026-05-05 and its README still calls the project experimental (7 of 10).)