If you look at a txn hash if you do a in-wallet swap you'll notice the fee MM takes goes to this multisig address which currently holds 9M (primarily 7M in WBTC, then ~2M in stables and defi majors) 0x2aCf35C9A3F4c5C3F4c78EF5Fb64c3EE82f07c45 (Insightful)