SPY perpetual
What the SPY book looks like right now: price, open interest, turnover and the hourly funding, read straight from the venue.
The whole index in one position
One contract instead of a basket: this follows SPDR S&P 500 ETF Trust directly, with no rebalancing and no expiry.
It keeps trading outside regular hours, so a move that starts overnight is priced here first rather than at the next open.
What the funding costs here
The hourly rate is +0.0005%, so a position held for a day pays or collects +0.0121%, and a week works out to +0.085%. Annualised at the current rate that is +4.43% — it costs the long side 4.43% a year at the current rate. The rate is recomputed continuously, so this is what today looks like, not a promise about next week.
Funding is what keeps the contract tethered to the underlying price. When it is positive the long side is crowded and pays the short side; when it flips, so does the payment. A rate that stays on one side for days is worth more attention than a large rate that lasts an hour.
How busy this book is
Over the last day $19.83M changed hands against $4.53M of open interest, so the market turns over about once a day, which is the profile of a book people hold rather than trade. Across 28,703 trades that averages $690.82 per trade.
The ratio matters more than either number alone: turnover tells you how easily you can get in and out, open interest tells you how much conviction is sitting there. A book with high turnover and low open interest is liquid but shallow — easy to enter, and nobody holding the other side of your view.
What a trade costs here
These numbers are ours, not the venue's. We record this order book every 5.5 seconds and measure how far from the mid a real market order would fill — 7,246,785 snapshots so far, counted only while the market was open, because off-hours the book sits wide and would flatter nothing.