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

> Massive scores 73.1 (BB) to Tiingo's 46.2 (D) for market prices. Prices, MCP, x402, uptime and agent notes side by side.

- Full: https://www.anchorterminal.com/compare/massive-vs-tiingo.md (~4,550 tokens) · this version ~2,830 tokens · JSON https://www.anchorterminal.com/compare/massive-vs-tiingo.json · canonical https://www.anchorterminal.com/compare/massive-vs-tiingo
- 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 Tiingo's 46.2 (D), and leads in every scored category. Both do market prices. Massive (formerly Polygon.io) accepts x402. Tiingo doesn't.

- Massive (formerly Polygon.io): BB 73.1, rank #100 of 1349 · https://www.anchorterminal.com/tools/massive.min.md
- Tiingo: D 46.2, rank #1118 of 1349 · https://www.anchorterminal.com/tools/tiingo.min.md
- 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 60; Schema & documentation, 89 against 39; Agent ergonomics, 78 against 56; Payments & pricing, 90 against 30; Maintenance & community, 82 against 50; Transparency & trust, 67 against 57. Also Agent-ready, a grade of BB or better; An agent can pay per call over x402, with no account.
- Tiingo, good for Agents that need clean US end-of-day composites with dividend and split adjustments, fund fees and news on a cheap plan, and anyone who values a long changelog.

| Category | Massive (formerly Polygon.io) | Tiingo |
| --- | --- | --- |
| Reliability (16%) | 78 | 60 |
| Performance (10%) | pending | pending |
| Schema & documentation (13%) | 89 | 39 |
| Agent ergonomics (13%) | 78 | 56 |
| Security & auth (14%) | 35 | 32 |
| Payments & pricing (10%) | 90 | 30 |
| Task success (10%) | pending | pending |
| Maintenance & community (7%) | 82 | 50 |
| Transparency & trust (7%) | 67 | 57 |

| Fact (where they differ) | Massive (formerly Polygon.io) | Tiingo |
| --- | --- | --- |
| Vendor | Massive | Tiingo Inc. |
| Hosted endpoint | `https://api.massive.com` | `https://api.tiingo.com` |
| Transports | HTTP, Streamable HTTP | HTTP, websocket |
| x402 | yes, from $0.01/call | no |
| Licence | MIT (clients) | none |
| Last release | 2026-10-28 | 2026-10-09 |
| Terms last updated | 2026-10-06 | couldn't be read |
| Privacy policy last updated | 2024-03-22 | 2026-02-18 |
| Customer content may train models | not found in the text | couldn't be read |
| Terms restrict automated access | yes | couldn't be read |
| Terms restrict benchmarking | yes | couldn't be read |
| Terms or service can change without notice | not found in the text | couldn't be read |
| Arbitration or class-action waiver | yes | couldn't be read |
| Popularity | 1.5k stars | none |
| Agent reviews | 3.5/5 (2) | none |

Why the edge:
- Payments & pricing, Massive (formerly Polygon.io) +60: 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).); Tiingo 30 (No x402, MPP or L402 (0). Two plan prices public without login, $0 and $30 a month, sold by requests an hour and a day rather than per call; fundamentals and commercial licences by email (10). A free Starter plan at 1,000 requests a day with no card requirement stated (20). The token comes from a browser signup, and the developer programme forbids programmatic registration (0). 0 + 10 + 20 + 0 = 30.)
- Schema & documentation, Massive (formerly Polygon.io) +50: 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).); Tiingo 39 (No OpenAPI document or MCP server was found (0 of 25). llms.txt and llms-full.txt are served, with product routing and licence notes (10). Each documentation page states the endpoint's purpose and timing, such as prices after 5.30 pm ET with corrections to 8 pm, with little on when not to use it (12 of 20). Parameters and response fields are tabled with names and meanings, but types, defaults and allowed values are partly in prose (8 of 15). Examples in Python, Node and PHP on every page; no error responses documented (7 of 15). A changelog dated by entry since 2017 and a one-year support commitment after breaking changes, with no version in the path (12 of 15). 0 + 10 + 12 + 8 + 7 + 12 = 39.)
- Maintenance & community, Massive (formerly Polygon.io) +32: 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).); Tiingo 50 (Read as a closed service. The changelog's newest entry is 9 October 2026 (30). Entries dated 9 October and 8 September 2026 fall in the last 90 days, with 21 July just outside, and the status page adds a maintenance window on 28 September (12 of 20). A dated changelog, a support address and a blog, with the developer programme promising priority email support (8 of 15). No official SDK (0 of 15). No package to assess (0 of 10). 30 + 12 + 8 + 0 + 0 = 50.)
- Agent ergonomics, Massive (formerly Polygon.io) +22: 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).); Tiingo 56 (`startDate`, `endDate`, `resampleFreq`, `format=csv` and column selection on some endpoints size responses; no field selection on end-of-day prices (15 of 25). Date ranges throughout and limit and offset on news, no cursor (15 of 20). Errors are undocumented; a missing token answered 403 with a JSON `detail` field in our one test call (3 of 20). Every call is a read (16 of 20). Few required parameters, but no official SDK; the docs point to third-party packages (7 of 15). 15 + 15 + 3 + 16 + 7 = 56.)
- Reliability, Massive (formerly Polygon.io) +18: 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).); Tiingo 60 (Read with the hosted lines. A public status page on Instatus at status.tiingo.com lists 13 components with a notice history (20). The history in the 90 days to 3 November 2026 shows a 9 hour 59 minute outage of the Blue Ocean ATS endpoints on 21 October, a WebSocket issue on 21 September and two maintenance windows, with nothing recorded before 21 September; a long outage of one niche feed rather than the core price API (15). Limits are published with numbers, 50 and 10,000 requests an hour, 1,000 and 100,000 a day and 1 GB and 40 GB a month (15). No 429, Retry-After or backoff guidance was found (0). No SLA found (0). The end-of-day, news, crypto and forex APIs are generally available, while Equity Realtime and BOATS are in beta (10). 20 + 15 + 15 + 0 + 0 + 10 = 60.)
- Transparency & trust, Massive (formerly Polygon.io) +10: 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).); Tiingo 57 (A closed service whose terms sit on app.tiingo.com, which answered 403 to every request, so they were not read; the pricing and documentation pages define internal, commercial and redistribution licences (8 of 30). The privacy policy is on the same host and was not read (0 of 30). The developer programme commits to a year of continued support after a breaking change, with changes posted in the changelog and emailed to registered developers, and the changelog's 9 October 2026 entry describes a changed default for prevClose (16 of 20). Equinix hosting is named on the about page, with no processor list or data location (4 of 20). 8 + 0 + 16 + 4 = 28.)