Avantis is the perpetuals exchange of Base, and its vault is the market maker: every trader who opens a position on Avantis is trading against one pool of stablecoin deposited by liquidity providers, and that pool collects the fees and the losses on the other side.

The arrangement is simple to hold and hard to watch. A deposit mints vault shares at the pool's current value, and the share price moves with the exchange's flow: fees and trader losses lift it, trader profits paid out lower it. The pool backs open interest far larger than its balance through the exchange's open interest multiplier, so a reserve is held against every open trade, and the vault measures how much of its capacity that reserve uses.

That utilization is what governs the way out. There is no queue and no lockup; a withdrawal or redemption settles in the block it is sent, unless it would push utilization to the withdraw threshold, in which case it reverts, because the vault will not let its liquidity providers pull the reserve out from under open trades. While the vault's fees are on, every exit also pays a collateral health fee that the vault manager steps with the health of the exchange's buffer. The exit you want is open or shut, cheap or dear, depending on numbers that move with every trade.

Every one of those numbers is a step in a plug: the share value and the exact quotes for depositing, minting, withdrawing and redeeming, the reserve and the utilization it implies, the threshold that closes exits, the fee and the switch that turns it on. Deposits and exits run when a condition is met rather than when a person is awake.

An exit that waits until utilization falls back below the threshold and fires in the first block it will land. A withdrawal held until the exit fee drops, then sent without a second look. A deposit that catches room under the cap the moment it opens.

Providing liquidity to a perpetuals exchange is a position whose exit depends on everyone else's trades. The providers who leave on their own terms are the ones whose exits are already written down as rules.