TradingDataCompare

IEX Cloud (Discontinued) vs Polygon.io (now Massive)

Head-to-head comparison of two trading data providers. Updated 2026-05-24.

Overall winner: Polygon.io (now Massive) — wins 3 of 6 comparison axes.

Side-by-Side Comparison

Feature IEX Cloud (Discontinued) Polygon.io (now Massive)
API Quality 3/5 4/5 ✓
Doc Quality 3/5 4/5 ✓
Free Tier No Yes ✓
Affiliate Program No No
Data Latency second tick
SDK Languages 5 languages 5 languages
Asset Coverage US Equities, US Options, Crypto, Forex, Commodities US Equities, US Options, Forex, Crypto, Global Indices
Historical Depth Service discontinued 2003–present (equities)
Starting Price N/A $0/mo
Rate Limits Service discontinued Free: 5/min; Starter: 15/min; Developer+: unlimited

IEX Cloud (Discontinued): Best For

  • Historical reference only

Not Ideal For

  • Any new project — service is shut down
Full IEX Cloud (Discontinued) review →

Polygon.io (now Massive): Best For

  • Algo traders
  • Fintech app developers
  • Options traders
  • Crypto quants

Not Ideal For

  • Tick-level HFT (DBZ format not available)
  • Institutional order book depth
Full Polygon.io (now Massive) review →

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