Liquidation
Your liquidation price moved and you didn't touch anything
You opened the position, wrote the liquidation price down, and went to do something else. You came back and the number is different. You did not place an order, you did not change the leverage, you did not deposit anything. It moved anyway.
Short answer
You are in cross margin. A cross position’s liquidation price depends on your available balance — everything in the cross account that is not this position’s own equity. It is not a property of your position. It is a property of your whole account, recomputed whenever any part of that account changes: another position’s mark moving, a deposit or withdrawal, or a fill anywhere that changes a size.
An isolated position does not do this — its backing is a dedicated allocation nothing else can reach. It still drifts slowly, because accrued fees and funding come out of equity, and that drift only ever runs one way: toward you.
What a liquidation price is actually made of
A liquidation price is not stored anywhere. It is solved, continuously, from the point where your equity would exactly meet maintenance margin.source
Equity = Collateral + UnrealizedPnL(Mark) − FeesDue − FundingDue
MM = Notional × MMR where MMR = 0.5 / MaxLeverage
Liquidation when Equity < MMTwo of those terms are fixed once you are in: your size and your entry. Everything else is a variable. And in cross margin, the collateral term is not a number you chose — a cross position’s liquidation price depends on available balance: everything in the cross account that is not that position’s own equity.source
In cross, the liquidation price is a property of the account, not of the position.
Your position is one claim on a shared pool. When the pool changes size, every claim on it is repriced — simultaneously, without anybody placing an order.
Three things that move it while you sit still
- Another cross position’s mark moved. Unrealized PnL on any cross position feeds the shared equity. Your ether short going into profit widens the liquidation distance on your bitcoin long. Your ether short going against you narrows it. Neither requires you to do anything, and mark updates every 200 milliseconds, so this is happening continuously.source
- Collateral changed. A deposit widens the distance on every cross position at once. A withdrawal narrows every one of them at once. Polymarket will not let you withdraw yourself directly into a margin call — the rule is that equity after the withdrawal must still cover initial margin — but that rule protects the account, not your comfortable buffer.source
- A fill anywhere in the cross account changed a size. Opening a new cross position consumes margin. Closing one releases it. A partial fill on a resting order you forgot about does both a little. Any of those changes the available balance and therefore every liquidation price drawing on it.
Does the liquidation price move in isolated margin?
In isolated margin every position gets its own dedicated allocation, and a liquidation closes only the affected position. The blast radius is one instrument, and new orders are blocked on that market alone rather than across the account.source
| Isolated | Cross | |
|---|---|---|
| What backs the position | Each position gets its own dedicated margin allocation. | All cross positions share the account's collateral. |
| Blast radius | One instrument. | Every cross position on the account. |
| Orders blocked when flagged | New orders blocked on the affected market only. | New orders blocked on every market for the account. |
| Moved by an unrelated position | No | Yes |
That is the practical argument for isolated: a liquidation price you can reason about, because the only inputs are ones you can see on one screen. The full comparison of the two modes is here, including the markets that reject cross outright.
Why an isolated liquidation price drifts anyway
If you have already checked and you are not in cross, this is what you are experiencing.
Look at the equity formula again. Two of its terms are subtractions: fees due and funding due. Both accumulate while you hold. Neither asks permission. Lower equity means the mark has less distance to travel before it meets maintenance margin — so the liquidation price creeps toward you, hour by hour, in a position you have not touched.source
Funding is the bigger of the two because it never stops. Polymarket settles it every hour, it runs in every session including when the underlying market is closed, and it is not zero in a flat market. With premium at zero, the fixed interest leg survives the formula, so a crypto long still pays +0.0013% of notional an hour.source
A week of funding, in dollars
Take an isolated long on Bitcoin, a 20x crypto market. Entry 100,000, size 0.1 — so $10,000 of notional — opened at 10x, which means a dedicated allocation of $1,000. Maintenance margin is the flat market rate of 2.50% of notional, derived from the market ceiling rather than from the leverage you picked. Assume the market does nothing at all for a week: premium is zero, mark never leaves entry, and you pay only the resting rate.
| At open | After 168 hours | |
|---|---|---|
| Funding paid | $0 | $21 |
| Equity backing the position | $1,000 | $979 |
| Liquidation price | 92,307.69 | 92,523.08 |
| Room before liquidation | 7.69% | 7.48% |
$21 of funding on $10,000 of notional moved the liquidation price up by $215.38 and took 0.22% off your room. Small, and unconditional. Hold for a month at the same rate and it is four times that. Hold through a period where the market is actually paying premium rather than resting, and the hourly rate can reach the 4% cap.source
The resting rate is a floor, not a forecast. What each market is paying right now is tracked here, and the calculator will run your own numbers.
What to do about it
- Monitor equity, not the liquidation price. Equity is the input; the liquidation price is an output that gets recomputed under you. Margin ratio — equity over maintenance margin — is the honest single number, and it is below 1.0 that the system starts closing you.source
- Keep a buffer that survives a bad hour elsewhere. In cross, size every position as though one of the others is about to go against you.
- Know that reduce-only arrives first. Between healthy and liquidated there is a margin-call state: equity below initial margin but still at or above maintenance margin. The account goes reduce-only. You can close or deposit; you cannot add. That transition is the alarm.source
- If a stable liquidation price matters more than capital efficiency, use isolated. You will tie up more collateral. In exchange the number stops depending on things you are not watching.
Before you conclude the number is haunted: liquidation is triggered against mark price, not the last trade on the chart. Mark is a median of three independently-built candidates and can sit somewhere the chart has not visibly been.
Questions people ask
Why does my Polymarket liquidation price change when I have not touched the position?
Because you are almost certainly in cross margin. A cross position's liquidation price is computed against the available balance in the account — everything in the cross account that is not that position's own equity. When another cross position's mark moves, or you deposit or withdraw collateral, or any fill anywhere in the account changes a size, the available balance changes and every cross liquidation price is recomputed at once.
Does the liquidation price move in isolated margin too?
Not from other positions, no. An isolated position is backed by its own dedicated margin allocation, so nothing happening on another market can touch it. It does still drift slowly, because accrued fees and funding are subtracted from equity, and lower equity means a nearer liquidation price. The drift is one-directional and against you.
How much does funding move an isolated liquidation price?
It depends on notional and rate, but the floor is not zero. With a flat market the funding formula still returns the fixed interest leg, so a crypto long pays +0.0013% of notional an hour. On $10,000 of notional that is $0.13 an hour and $21 a week, taken straight off equity — which pulls the liquidation price toward the mark by a small, computable amount every hour you hold.
Which price is my liquidation price measured against?
Mark price. Polymarket builds mark as the median of three independently-constructed candidates and updates it 5 times a second, and mark is what drives unrealized PnL, margin checks and liquidation triggers. The last trade price on the chart margins nothing. A liquidation can happen at a level the chart appears never to have reached.
Will I get a warning before liquidation?
There is a state between healthy and liquidated. When equity falls below initial margin but is still at or above maintenance margin, the account is in margin call and goes reduce-only: you can close or shrink exposure or deposit collateral, but you cannot add risk. Liquidation only begins once equity falls below maintenance margin.
Does adding collateral push my liquidation price further away?
Yes. Backing and liquidation distance move together: more collateral behind a position means the mark has to travel further before equity meets maintenance margin. In cross, a deposit widens the distance on every cross position at once, because they all draw on the same balance.
Can a liquidation on one cross position close the others?
It can. A cross liquidation evaluates the whole cross account rather than one instrument, closes positions one at a time, and blocks new orders on every market for the account while the flag is up.