Extended vs Ostium Funding Arbitrage
8 shared markets · net of estimated fees · updated every few minutesExtended and Ostium both quote 8 of the same perpetual markets, so a delta-neutral position can be split across the two and collect the difference in their funding. The widest spread on a market with real depth is WTI — long Extended / short Ostium at 14.6% net APR — but the median across all shared markets is 14.5%, which is the number worth planning around.
The long leg is whichever venue prices funding lower for that market. It is a property of the MARKET, not of the exchange, and it flips as rates move: here 4 markets go long on Extended and 4 on Ostium. 8 markets clear 5% net APR, 6 clear 10%.
How this pair behaves
Extended pays funding every 1h on 153 markets; Ostium pays every 1h on 54 markets. Both sides settle on the same clock, so a position opened here collects or pays on both legs at once — the spread you see is the spread you get. Extended quotes 153 perpetual markets in total and Ostium quotes 54; the 8 they share are what this page ranks. Across its own book Extended runs a median funding rate of 5.3% and Ostium 0.0% — the two sit on opposite sides of zero, which is why this combination throws up spreads at all.
Spreads by market
top 8 of 8 by net APR| Market | Long | Short | Net APR | Gross | 7d avg | Thin leg vol |
|---|---|---|---|---|---|---|
| BB | Extended | Ostium | 70.5% | 78.0% | -9.9% | $3K |
| SKHY | Extended | Ostium | 61.4% | 68.3% | +7.1% | $25K |
| BMNR | Ostium | Extended | 45.9% | 53.4% | +5.2% | $259K |
| WTI | Extended | Ostium | 14.6% | 20.0% | +26.5% | $15.9M |
| XAU | Ostium | Extended | 14.4% | 19.5% | +0.7% | $48.4M |
| MRNA | Extended | Ostium | 11.9% | 20.1% | -1.2% | $4K |
| XAG | Ostium | Extended | 8.8% | 13.9% | +7.0% | $5.0M |
| ETH | Ostium | Extended | 6.1% | 11.4% | +9.1% | $96.3M |
Net APR subtracts entry and exit fees, both legs' bid/ask spread and estimated slippage from the gross funding spread. The 7-day average is historical gross funding for the same pair: a current rate close to it suggests the spread has persisted, one far above it is usually a spike that will decay.
Coverage note: Extended and Ostium share 8 markets, 4 of them with real depth — below the 10 markets / 5 liquid this page treats as full coverage, so this is a thin sample rather than a picture of the pair.
Extended vs Ostium — FAQ
How many markets can you arbitrage between Extended and Ostium?
8 perpetual markets are quoted on both Extended and Ostium right now. 8 of them show a net spread of at least 5% APR after estimated fees, and 4 have at least $1M of 24h volume on the smaller leg.
What is the best Extended / Ostium funding spread right now?
WTI: long Extended and short Ostium for about 14.6% net APR after estimated fees, counting only markets with at least $1M of 24h volume on the smaller leg. The median across all 8 shared markets is 14.5%, so the top of the list is not typical.
Which side pays on the Extended / Ostium pair?
It varies by market: Extended is the long (funding-receiving) leg in 4 of the shared markets and Ostium in the other 4. The direction is set per market by which venue currently prices funding lower.
Trading the Extended / Ostium spread
The trade is one position split across two venues: long the exchange paying the more negative funding, short the one paying the more positive, in the same size. What limits it is not the headline APR but the smaller leg's liquidity, the fees on both sides, and how long the spread survives — funding decays and flips, often within hours. Venue detail: Extended funding rates · Ostium funding rates; the full calculation is in the methodology.