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Open interest: how much money is standing in positions
Volume counts how many times something changed hands; open interest counts what stayed. The difference between the two is the entire meaning of this number.
Open interest is the sum of all positions that have not been closed. Not turnover but the remainder: how much money is standing in contracts right now. One trader who opens and closes a position a hundred times in an hour produces enormous volume and ZERO addition to open interest. And conversely: one large position opened in the morning and untouched until evening produces almost no volume yet shows in open interest all day.
It grows only when new money arrives
Every contract has two sides, and both open at the same moment. So open interest increases only if a NEW buyer meets a NEW seller. If the buyer is closing a short and the seller is closing a long, the trade happens, volume rises and open interest falls: two people left the market. That is what makes it the only honest counter of how much money is in play.
Four combinations, and only four
| Price | Open interest | What it means |
|---|---|---|
| rising | rising | new buyers arriving — the move is funded by money |
| rising | falling | shorts closing; there is a rally but no new money |
| falling | rising | new sellers arriving — the pressure is real |
| falling | falling | longs leaving; often the end of the fall, not the start |
One decline, two different meanings
Price went from 64,200 to 61,800 — minus 3.7%. Case one: open interest over that period rose from $180 million to $310 million. New sellers arrived and took shorts: the decline was paid for with fresh money and has someone to continue it. Case two: the same price move, but open interest fell from $310 million to $180 million. Nobody new arrived — longs were leaving, each on their own stop. The second decline usually ends where the stopped-out traders run out; the first does not.
Treating rising open interest as bullish
On its own the number has no side. It only says there is more money in the market; who brought it, buyers or sellers, is not visible from it. Meaning appears ONLY paired with price, which is why the table above has four rows rather than two. Reading open interest apart from price is the same as reading volume apart from the candle's direction.
Comparing coins by absolute size
This coin has $300 million of open interest and that one has $30 million, so the first is more interesting — the conclusion is empty. They are different sizes: for a large coin $300 million may be an ordinary Tuesday, while for a small one $30 million is an all-time high. Compare either with the coin's own turnover or with its own history. That is exactly why we put a monthly rank next to the number.
The dollar trap: the number falls when the price falls
Open interest can be counted in coins or in dollars. We show dollars so different instruments are comparable. But there is a side effect worth remembering: if price falls 30% and nobody touches their positions, dollar open interest will also show minus 30%. Nobody left; only the valuation changed. So a sharp drop in open interest during a sharp drop in price does not by itself prove an exit — check the hourly change next to the hourly price change.
The screener has a column for the hourly change in open interest — it sits next to the price change on purpose, so the two are read together. Find a coin where price is falling and open interest is rising, and see what happened over the next hour. Then find the opposite case. One pair of observations is worth more than ten explanations read.
Open interestTwenty cases across four cells
Take twenty notable moves on your instruments and sort them into the four cells of the table: what price did and what open interest did. For each, write one number for what followed — how far price travelled in the same direction over the next hour. Add them up per cell and compare the averages. For most people price down with interest down gives a noticeably smaller follow-through than price down with interest up — and that is your own measurement, not somebody's claim.
Volume is enormous and open interest has not changed. What happened?
Positions changed hands, but their total number stayed the same: for every new entrant there was someone leaving. That is a picture of active churn, not of money flowing in. It often happens in a range, when some read it as the end of a decline and others as a pause before more. By itself it is not a signal in either direction, but it answers whether the move is funded by fresh money: it is not.
Why does falling open interest during a falling price often mean the end of the move rather than its start?
Because in that case it falls due to longs CLOSING, and closing is finite. Everyone stopped out sells once and then sells no more — they are already out of the market. When there are none of them left, the pressure disappears by itself, with no support level on the chart required. If open interest RISES during a decline, new sellers are arriving and the move still has fuel.