Funding rate carry calculator
Long spot, short the perpetual, same size. The legs offset, so what is left is the funding payment — minus the four taker legs it costs to open and close. That round trip is 0.38% of notional at the fee tier below, which is why the holding period decides this trade far more than the funding rate does.
Same cost model and 0.010% per 8h entry threshold our own engine uses. Your fee tier decides this trade more than anything on this page, so it matters whether we are paid when you open an account — we disclose that. Nothing here is financial advice.
Your position
Fees default to the tier modelled in src/alpha/carry.py, plus 2bps of slippage per leg. Lower them to your own tier and the break-even moves with them — it is the single biggest lever on this trade.
What it earns
This clears its costs after 12.7 days.
Costs are paid once; carry accrues every 8 hours. Past the break-even the whole rate is yours, which is why holding period matters more than the rate.
This arithmetic flatters reality in two ways, both of them material. It assumes the funding rate holds for the whole hold, and it prices neither basis risk nor margin. Spot and perp are not the same instrument: a wider basis at exit is a real loss that can exceed weeks of carry. And “delta-neutral” is not “liquidation-proof” — the short perp leg showed adverse excursions of +116% on BTC and up to +400% on SOL over 31 to 98-day holds, so portfolio margin is a prerequisite, not an optimisation. Nothing here is financial advice.