What Is a “Rug Pull” and How Does It Relate to Contract Immutability?

A "rug pull" is a malicious maneuver where developers suddenly drain the liquidity from a decentralized exchange (DEX) or lending pool, leaving investors with worthless tokens. It relates to immutability because if the contract code contains a hidden function allowing the developers to unilaterally withdraw funds, the lack of immutability (or the presence of an unauthorized 'owner' function) is the exploit vector, making the project non-trustless.