IEX Cloud (Discontinued) VS Polygon.io (now Massive)
Head-to-head market data API comparison.
UPDATED 2026-05-24 · 7 axes scored
WINNER · POLYGON.IO (NOW MASSIVE) · 3/7 AXES
Quick Decision
▶ PICK IEX CLOUD (DISCONTINUED) IF DATA-API
- Historical reference only
▶ PICK POLYGON.IO (NOW MASSIVE) IF DATA-API
- Algo traders
- Fintech app developers
- Options traders
- Crypto quants
Side-by-Side Matrix
| METRIC | IEX CLOUD (DISCONTINUED) | POLYGON.IO (NOW MASSIVE) |
|---|---|---|
| API Quality | 3/5 | 4/5 |
| Doc Quality | 3/5 | 4/5 |
| Data Latency | second | tick |
| SDK Languages | 5 languages | 5 languages |
| Free Tier | No | Yes |
| Affiliate Program | No | No |
| Asset Coverage Breadth | 5 classes | 5 classes |
| 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 |
Asset Class Coverage
Where the two providers overlap and where each has unique coverage.
| ASSET CLASS | IEX CLOUD (DISCONTINUED) | POLYGON.IO (NOW MASSIVE) |
|---|---|---|
| Commodities | ✓ Covered | — |
| Crypto | ✓ Covered | ✓ Covered |
| Forex | ✓ Covered | ✓ Covered |
| Global Indices | — | ✓ Covered |
| US Equities | ✓ Covered | ✓ Covered |
| US Options | ✓ Covered | ✓ Covered |
| TOTAL CLASSES | 5 | 5 |
Only IEX Cloud (Discontinued)
Commodities
Only Polygon.io (now Massive)
Global Indices
Shared · 4
US Equities · US Options · Crypto · Forex
Pricing Tier Map
Full tier ladder side-by-side · names and prices as published by each provider · 1 vs 4 tiers.
IEX CLOUD (DISCONTINUED) · 1 TIERS
01
Discontinued N/A
IEX Cloud shut down on August 31, 2024
POLYGON.IO (NOW MASSIVE) · 4 TIERS FREE TIER
01
Stocks Basic $0/mo
EOD data, 5 calls/min
02
Stocks Starter $29/mo
15-min delayed data
03
Stocks Developer $79/mo
15-min delayed data, unlimited calls
04
Stocks Advanced $199/mo
Real-time data, WebSocket, full history
▲ Free Tier · Free tier (Stocks Basic): 5 API calls/min, EOD data only, no real-time
Technical Stack Fit
SDK languages and data formats determine integration cost for your existing codebase.
| DIMENSION | IEX CLOUD (DISCONTINUED) | POLYGON.IO (NOW MASSIVE) |
|---|---|---|
| API Types | REST · WebSocket · SDK | REST · WebSocket · SDK |
| SDK Languages | Python · JavaScript · Java · Go · Ruby | Python · JavaScript · Go · Kotlin · Swift |
| Data Formats | JSON | JSON |
| Rate Limits | Service discontinued | Free: 5/min; Starter: 15/min; Developer+: unlimited |
| Latency Class | second | tick |
Fit Profile
IEX CLOUD (DISCONTINUED) · PROFILE DATA-API
Best For
- Historical reference only
Not Ideal For
- Any new project — service is shut down
Full IEX Cloud (Discontinued) Review
POLYGON.IO (NOW MASSIVE) · PROFILE DATA-API
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
Adjacent Comparisons
Related matchups — same category first, then cross-category for context.
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