Perpetual futures venues promise that a losing position cannot cost more than the margin backing it. Auto-deleveraging is the mechanism that keeps that promise when a liquidation fails to fill.
Liquidation can leave a hole
When a position crosses its maintenance margin threshold, the venue takes it over and tries to close it in the market. Ideally it fills at a price better than the bankruptcy level.
In fast conditions there may be no bid deep enough. The position closes below the level at which the margin is exhausted, and the shortfall belongs to somebody.
It cannot be charged back to the trader, because contracts are not designed to create debts beyond posted collateral. So the venue must absorb it from elsewhere.
The insurance fund absorbs the first layer
Venues accumulate an insurance fund from liquidations that close better than the bankruptcy price. Those surpluses are retained rather than returned to the liquidated trader.
The fund then pays shortfalls when liquidations close worse. Over ordinary conditions the surpluses exceed the shortfalls and the balance grows.
Fund balances are usually published continuously, because they are the buffer standing between a disorderly move and the rest of the venue's users.
Deleveraging is what happens after the fund
If the fund is depleted, the venue closes positions on the opposite side of the market to net out the exposure it cannot cover.
Selection is ranked, typically by profit and leverage combined, so the most profitable and most leveraged counterparties are reduced first.
Affected traders are closed at the bankruptcy price of the failed position, not at the market price, and receive no choice in the matter.
Why winners bear the cost
The design reflects an accounting reality: in a closed derivatives system, gains and losses must sum to zero across all participants.
If a loser cannot pay in full, the difference has to be taken from the corresponding winners, since there is no external balance sheet standing behind the contracts.
Traditional clearing houses solve this with member capital and default funds. Crypto venues that lack that structure use deleveraging as the equivalent backstop.
What the indicator on a position means
Most venues display a queue indicator showing how close a position sits to being selected. It moves with profit and leverage rather than with market direction.
A highly profitable, highly leveraged position sits near the front of the queue precisely when volatility makes deleveraging most likely.
The practical consequence is that a correct directional view can still end early, which is a venue design feature rather than a malfunction.