Aster vs Ostium Funding Arbitrage
6 shared markets · net of estimated fees · updated every few minutesAster and Ostium both quote 6 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 XAU — long Ostium / short Aster at 1.2% net APR — but the median across all shared markets is 2.3%, 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 3 markets go long on Aster and 3 on Ostium. 2 markets clear 5% net APR, 2 clear 10%.
How this pair behaves
Aster pays funding every 4h on 143 markets and every 8h on 95 markets; Ostium pays every 1h on 52 markets. The two clocks differ, so one leg settles while the other is still accruing: a position held for only a few hours can pay one side without ever collecting from the other. Aster quotes 248 perpetual markets in total and Ostium quotes 52; the 6 they share are what this page ranks. Across its own book Aster runs a median funding rate of 10.9% 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 6 of 6 by net APR| Market | Long | Short | Net APR | Gross | 7d avg | Thin leg vol |
|---|---|---|---|---|---|---|
| NFLX | Ostium | Aster | 52.0% | 62.8% | +1.1% | $337K |
| SKHY | Aster | Ostium | 42.9% | 49.7% | +7.0% | $524K |
| GOOGL | Aster | Ostium | 2.4% | 9.9% | +6.7% | $426K |
| AMZN | Aster | Ostium | 2.2% | 9.2% | +8.0% | $174K |
| XAU | Ostium | Aster | 1.2% | 6.4% | -0.1% | $2.3M |
| ETH | Ostium | Aster | 0.7% | 6.2% | +7.8% | $267.6M |
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: Aster and Ostium share 6 markets, 2 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.
Aster vs Ostium — FAQ
How many markets can you arbitrage between Aster and Ostium?
6 perpetual markets are quoted on both Aster and Ostium right now. 2 of them show a net spread of at least 5% APR after estimated fees, and 2 have at least $1M of 24h volume on the smaller leg.
What is the best Aster / Ostium funding spread right now?
XAU: long Ostium and short Aster for about 1.2% net APR after estimated fees, counting only markets with at least $1M of 24h volume on the smaller leg. The median across all 6 shared markets is 2.3%, so the top of the list is not typical.
Which side pays on the Aster / Ostium pair?
It varies by market: Aster is the long (funding-receiving) leg in 3 of the shared markets and Ostium in the other 3. The direction is set per market by which venue currently prices funding lower.
Trading the Aster / 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: Aster funding rates · Ostium funding rates; the full calculation is in the methodology.