What it is
A reading of how much leverage is held on a perps venue (its open interest) and which way that pile is moving over the week.
Why it matters
Open interest is the size of the bet the market has placed with borrowed conviction. Rising open interest while spot liquidity stays flat is pressure, not depth: more positions riding on the same thin book, which is exactly the setup that turns an ordinary move into a cascade of liquidations. A falling tide is the opposite, leverage being worked off, often after a flush.
How we read it
We read the open interest held now against where it stood a week ago, and surface the venues building or shedding leverage fastest, alongside the largest standing piles. The magnitude is dollars of open interest, so it ranks beside the liquidity readings even though it measures pressure rather than flow.
What it cannot tell you
Open interest is a level, not a direction: a large pile can sit calmly for weeks, and a rise does not say which way price will break, only that more is riding on it. We keep it out of the net-flow figure for that reason. Cross-venue comparisons also depend on consistent reporting, which is an estimate.