Kalshi vs Ostium

Ostium leads on all 3 live benchmarks. Ostium wins on Most tradable markets on a perp DEX, live count per venue (83 vs 21), Perp DEX asset breadth (74 vs 4), Perp DEX volume to open interest (0.365x vs 40.5x). Data as of 2026-09-24 UTC.

Read methodology Last measured Window: rolling 24h3 shared benchmarks
Kalshi logo
Kalshi

CFTC-regulated US prediction market exchange. REST trade API (trade-api/v2) with documented per-tier rate limits; the market data WebSocket requires authentication.

Ostium logo
Ostium

Arbitrum-based perp DEX specialized in RWA exposure including FX, commodities and indices.

Side by side measurements

Perp DEX asset breadth: non-crypto markets live, stocks + indices + forex + commodities

Trading

Kalshi

Trails

4

p99
4
rank
#14
samples
2,876

Ostium

Leads

74

p99
74
rank
#7
samples
2,876
Non-crypto markets
Kalshin/aOstiumn/a

Counts reflect each venue's live market catalog at query time, mainnet only. The asset class comes from the venue's own metadata where it publishes one; Hyperliquid HIP-3 dexes and dYdX publish none, so their symbols are matched against the crypto markets the other venues list and a fixed table of forex, commodity and index names. Tokenized gold (PAXG, XAUT) is a crypto token and is not counted. A market counts once whether it trades 24/7 or only during exchange hours.

Rolling 24h · Non-crypto marketsRaw JSON

Perp DEX volume to open interest: 24h turnover per dollar of OI, live

Trading

Kalshi

Trails

40.5x

p99
43.7x
rank
#22
samples
2,876

Ostium

Leads

0.365x

p99
0.578x
rank
#2
samples
2,876
Volume / OI (24h)
Kalshin/aOstiumn/a

The ratio is a screen, not a verdict. Both terms are the venue's own figures (24h volume and open interest as each API reports them, in USD), so a venue that counts both legs of a fill moves its ratio without changing anything real. A very low ratio (Ostium, 0.2x) means positions held for days on thin daily volume; a very high one (Kalshi, above 40x) means a day of trading dwarfs what stays open. The bands in the methodology say what each range usually means.

Rolling 24h · Volume / OI (24h)Raw JSON

Frequently asked questions

Kalshi vs Ostium: which one is better?

Kalshi and Ostium are compared on 3 shared OpenChainBench benchmarks. Ostium leads on Most tradable markets on a perp DEX, live count per venue. See the live table on this page for every metric.

Which has the higher active markets, Kalshi or Ostium?

On the Most tradable markets on a perp DEX, live count per venue benchmark, Ostium leads at 83 versus Kalshi at 21. Live measurement is updated continuously by the OpenChainBench harness.

How is the Kalshi vs Ostium comparison measured?

Every benchmark on this page uses the same open methodology, published at https://openchainbench.com/methodology. Data is CC-BY-4.0. Measurement harnesses are MIT-licensed.

Related comparisons

How this pair was selected

Auto-generated pairs require: both providers in the same benchmark for seven consecutive days, at least 1000 samples per provider, observable third-party search demand, and a public /products/[slug] page on OCB. Editorially curated pairs (like this one) may publish early when search demand is high and data is accruing; panels with fewer than 100 samples are shown as provisional. The full pair ledger is versioned in the public repo.

Live data refreshes via ISR within 60 seconds of a new run. Sources are the same Prometheus queries surfaced on the parent benchmark pages.