Marketstack VS Polygon.io (now Massive)
Head-to-head market data API comparison.
UPDATED 2026-05-27 · 7 axes scored
WINNER · POLYGON.IO (NOW MASSIVE) · 2/7 AXES
Quick Decision
▶ PICK MARKETSTACK IF DATA-API
- Web app developers
- Simple stock charts
- Basic portfolio apps
- Budget-conscious indie devs
▶ PICK POLYGON.IO (NOW MASSIVE) IF DATA-API
- Algo traders
- Fintech app developers
- Options traders
- Crypto quants
Side-by-Side Matrix
| METRIC | MARKETSTACK | POLYGON.IO (NOW MASSIVE) |
|---|---|---|
| API Quality | 3/5 | 4/5 |
| Doc Quality | 4/5 | 4/5 |
| Data Latency | minute | tick |
| SDK Languages | 1 languages | 5 languages |
| Free Tier | Yes | Yes |
| Affiliate Program | Yes | No |
| Asset Coverage Breadth | 6 classes | 5 classes |
| Asset Coverage | US Equities · Global Equities · ETFs · Global Indices · Bonds · Commodities | US Equities · US Options · Forex · Crypto · Global Indices |
| Historical Depth | 30+ years (annual EOD); intraday on Professional+ | 2003–present (equities) |
| Starting Price | $0/mo | $0/mo |
| Rate Limits | Free: 100/mo; Basic: 10k/mo; Pro: 100k/mo; Business: 500k/mo | Free: 5/min; Starter: 15/min; Developer+: unlimited |
Asset Class Coverage
Where the two providers overlap and where each has unique coverage.
| ASSET CLASS | MARKETSTACK | POLYGON.IO (NOW MASSIVE) |
|---|---|---|
| Bonds | ✓ Covered | — |
| Commodities | ✓ Covered | — |
| Crypto | — | ✓ Covered |
| ETFs | ✓ Covered | — |
| Forex | — | ✓ Covered |
| Global Equities | ✓ Covered | — |
| Global Indices | ✓ Covered | ✓ Covered |
| US Equities | ✓ Covered | ✓ Covered |
| US Options | — | ✓ Covered |
| TOTAL CLASSES | 6 | 5 |
Only Marketstack
Global Equities · ETFs · Bonds · Commodities
Only Polygon.io (now Massive)
US Options · Forex · Crypto
Shared · 2
US Equities · Global Indices
Pricing Tier Map
Full tier ladder side-by-side · names and prices as published by each provider · 5 vs 4 tiers.
MARKETSTACK · 5 TIERS FREE TIER
01
Free $0/mo
100 req/mo, EOD only, 1-year history
02
Basic $9.99/mo
10,000 req/mo, intraday access, all asset types
03
Professional $49.99/mo
100,000 req/mo, real-time updates (sub-15min), commodities
04
Business $149.99/mo
500,000 req/mo, priority support
05
Enterprise Custom
Higher limits + SLA
▲ Free Tier · 100 requests/mo, EOD only, 1-year history
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 | MARKETSTACK | POLYGON.IO (NOW MASSIVE) |
|---|---|---|
| API Types | REST | REST · WebSocket · SDK |
| SDK Languages | REST-only (community Python wrappers exist) | Python · JavaScript · Go · Kotlin · Swift |
| Data Formats | JSON | JSON |
| Rate Limits | Free: 100/mo; Basic: 10k/mo; Pro: 100k/mo; Business: 500k/mo | Free: 5/min; Starter: 15/min; Developer+: unlimited |
| Latency Class | minute | tick |
Fit Profile
MARKETSTACK · PROFILE DATA-API
Best For
- Web app developers
- Simple stock charts
- Basic portfolio apps
- Budget-conscious indie devs
Not Ideal For
- Real-time HFT
- Tick-level analysis
- Options/futures traders
- Native SDK lovers
Full Marketstack 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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