🚨 New paper alert 🚨 Active Liquidity On Chain: Evidence from PropAMMs Across Chains w/ Ozan Solmaz @jason_of_cs Liquidity providers on traditional AMMs such as Uniswap are passive and suffer from adverse selection. As a result, their price only moves through trades. When an external market moves, these LPs get picked off on their stale quotes. PropAMMs, a new design, emerged in 2024 attempting to combat this. In them, a single operator quotes from its own inventory and reprices actively. By 2026, propAMMs carried more than half of SOL/USDC volume on Solana and had been found, among other chains, on Base and Monad. Our work seeks to elucidate the benefits of this new design both for LPs and for retail users. Do propAMM operators really have an edge over passive LPs, and if so, where does this edge come from? Can propAMMs offer tighter quotes to retail users? We measured a full year of propAMMs on Solana, Base and Monad, and decoded the closed-source on-chain logic of Tessera, the largest propAMM on Base. The result: propAMMs have a measurable edge over passive LPs: two seconds after a fill, propAMMs earn 0.37 bps on Solana, 1.19 bps on Base and 1.69 bps on Monad, while passive LPs on AMMs comparatively lose 0.22, 0.62 and 2.06 bps. We trace the edge to four sources: 🟠 Cheap, frequent repricing: updates use at least 25 times less resources than swaps on Solana, and 5 to 15 times less on Base and Monad. Generally, the default block order on all three chains is by priority fee per unit of computation. Thus, an update pays far less than a swap for the same priority placement. 🟠 Pricing by counterparty: five of the six largest Solana propAMMs offer tighter spreads to aggregator flow than to non-aggregator flow. For Tessera on Base, we show that it whitelists, penalizes or blacklists individual addresses. 🟠 Arbitrage against AMMs: when a reference price moves, propAMMs reprice while AMMs do not, and arbitrageurs trade the two. A propAMM fills at its updated quote, so it may break even on these legs on Solana and Base and even earn 1.55 bps on Monad. 🟠 Spoofing: aggregators route on the quote from the end of the previous block. For Tessera on Base, we show that the operator consistently raises its default fee early in the block and lowers it again late in the block, so aggregators read stale state that carries the lower fee. As a result, only 39% of swaps execute at the quoted price, and the average swap receives 1.08 bps less. The second question we ask is: can propAMMs offer users tighter quotes as a result of their edge? The answer is yes: on fills that arrive while the price is not moving (our proxy for retail flow) propAMMs take 0.26 bps on Solana, 1.26 bps on Base and 1.62 bps on Monad, where AMMs take 2.59, 1.38 and 8.60 bps respectively. Retail also makes up a larger share of propAMM volume: 32%, 43% and 17% on Solana, Base and Monad, against 9%, 16% and 8% on AMMs. What did we learn? PropAMMs avoid the losses of passive liquidity provision, yet still manage to give retail tighter quotes. However, users also have to bear the cost of spoofing, which we expect to change as aggregators move to an on-chain methodology. Link: arxiv.org/abs/2609.38056