Jito Labs, a Solana MEV startup, reportedly declared on Friday that it will suspend the mempool functionality provided by the Jito Block Engine in response to an increase in sandwich attacks against the Solana blockchain. MEV sandwich attacks transpire when MEV searchers capitalize on the price volatility of an asset. Profiting from the user's trade, the searcher advances a substantial purchase order that they anticipate will increase the price of the asset and subsequently sells it immediately after a victim purchases it. The hiatus was a deliberate decision reached by Jito Labs subsequent to discussions with key stakeholders in the Solana ecosystem and the Jito Labs team.

The action was greeted with a variety of reactions from industry participants. A validator generates blocks on Ethereum by amassing transactions from a mempool, which serves as a staging area prior to the block's construction and on-chain confirmation. Maximum extractable value (MEV), which is frequently acquired by validators at the detriment of retail merchants, is contingent on the sequence in which these transactions are executed within the block. In contrast to Ethereum, which incorporates mempools by design, Solana does not disclose the block processor in advance. In order to enable validators to capture MEV on Solana, Jito Labs and other firms developed infrastructure that implemented mempool functionalities.

Dan Smith, a research analyst at Blockworks, remarked that MEV had been the sole driver of JTO's growth, suggesting that the suspension of mempool functionality could make it difficult to provide value to JTO token holders. The primary functions of Jito's native token (JTO) are to enable community members to participate in governance and to provide holders with MEV rewards. These rewards are acquired via MEV that the Jito protocol generates and subsequently redistributes. As of this writing, JTO is trading at $2.72 on CoinGecko, representing a 1.6% decrease from the previous week's price.

Ren Yu Kong, a research analyst at Blockworks, stated that Telegram bot users, who frequently set a high slippage amount to get their exchange through but then experience the utmost slippage due to being sandwiched, could potentially benefit from this decision. This occurs significantly less frequently since Jito's mempool was deleted. Kong observes, however, that searchers and arbitragers would likely be incentivized to spam the network in the absence of Jito's mempool, resulting in failed transactions and wasteful validator resources. Jito failed to provide a response to Blockworks' request for comment prior to the scheduled publication time.