How Does the Concept of a “Virtual Swap” Relate to Capital Efficiency in AMMs?

A virtual swap is a mechanism used in certain AMM designs, such as Balancer's Vault architecture, where a trade is executed without actually moving the underlying tokens in the pool's reserves. Instead, the trade updates the internal accounting of the pool's tokens.

This concept is more related to the implementation of the AMM's logic and its security model rather than capital efficiency. Capital efficiency is primarily achieved through mechanisms like concentrated liquidity or stableswap curves, which focus on maximizing liquidity around the current price.