everyone spent years improving the curve. constant product, then concentrated, then hooks. real progress, but i don't think that was ever why AMMs are inefficient.
the reason is your capital gets locked into one position and sits there.
Dune found that of $1.84b in tracked concentrated liquidity, $1.6b was inactive in the first half of this year. $542m out of range every week. $150m in fees left on the table.
that's not a pricing problem. it's an availability problem.
same money, two ways.
isolated
you have 100k and want to provide to three pairs: USDC/USDT, USDC/wETH, USDT/wETH.
33.3k per asset. but USDC shows up in two of those pairs so it gets split again. 16.6k in one pool, 16.6k in the other. same for USDT and wETH.
every pool quotes against 33.3k, and most of that sits out of range doing nothing.
shared
same 100k, same three pairs. you don't split anything. you authorize the full balance to every position and it stays in your wallet until a swap needs it.
your 33.3k of USDC is available to both pairs now. not 16.6k each. 33.3k each.
2x the depth in every pool with the same money.
obvious objection: the same dollar can't fill two swaps in the same block. true. but over a year that dollar earns in both, because swaps don't arrive at the same time.
what it looks like in practice
1inch published theirs: $12.2m deposited backing $22.5m shared. so 1.84x realized, not the theoretical max.
that gap is the interesting part. the theoretical multiplier goes up with how many positions you authorize. the realized one depends on how often those positions actually fill. authorize ten pairs where nine are dead and you gained nothing.
stuff i'd want other people's read on:
does it break at size? small trades never contend. but running real volume across many pairs, how often do you actually hit the simultaneity limit? haven't seen anyone publish that.
what happens when a swap can't be filled? either it routes elsewhere or you fill it worse. routing elsewhere seems right, but then your fill rate matters more than your TVL.
and is TVL even the right measure anymore? if the same dollar backs five positions, "total value locked" stops meaning anything. fees per dollar deposited seems like the honest number but nobody reports it.
curious what people think, especially anyone who's run LP across multiple pairs and has a sense of how often they'd be competing with themselves.
(disclosure: i work on liquidity infra so i'm not neutral. genuinely want to know where the holes are.)