Share this article

Solana Heavyweights Wage War Against Private Mempool Operators

Validators found to be facilitating sandwich attacks face stiff penalties.

Updated Jun 10, 2024, 5:37 p.m. Published Jun 10, 2024, 4:52 p.m.
Solana Hacker House in Miami (Danny Nelson/CoinDesk)
Solana Hacker House in Miami (Danny Nelson/CoinDesk)

A group of Solana validators are facing financial penalties for allegedly facilitating economic attacks against crypto traders.

Over 30 validator operators were kicked off the Solana Foundation Delegation Program over the weekend, a source familiar with the matter said. While they remain validators on the network, they're no longer eligible to receive what amounted to payout boosters for validating transactions on the Solana blockchain. Many of the operators were Russians, another source said.

STORY CONTINUES BELOW
Don't miss another story.Subscribe to the Crypto Daybook Americas Newsletter today. See all newsletters

The purge escalates a months-long shadow war between heavyweights of the Solana validator ecosystem and an underground economy of validators believed to be exploiting traders for profit through what's known as a "sandwich attack," whereby bots frontrun and backfill trades that haven't yet been executed.

It's among the more notorious maximal extractable value, or MEV, strategies possible on blockchains that rely on mempools, which are essentially waiting rooms for unconfirmed transactions. Solana doesn't have a native mempool, but the wildly popular validator software developed by Jito Labs once did.

In March, at the height of Solana's meme coin frenzy, Jito Labs shut off the mempool function because it was exposing traders to near-constant and costly sandwich attacks. Jito's CEO framed the move as being in the best interest of the Solana ecosystem even if it cut off one potential revenue stream for validators, the server operators who keep things running on this decentralized network.

Rather than completely solve the problem, Jito's move pushed it underground. Whispers quickly emerged of private mempools whose operators were making at times hundreds of thousands of dollars by enabling sandwich attacks.

One proposal from infrastructure operator DeezNode offered validators who opted into its private mempool 50% of the profits generated by MEV, according to documents reviewed by CoinDesk.

A Jito Foundation governance post from late Sunday indicates 10% of the JitoSOL pool is being delegated to validators running private mempools. The Jito Foundation has proposed imposing further economic penalties on those validators by way of restricting yet more staked SOL.

Solana Foundation's own delegation blacklist is small as a portion of the delegation program. It targets a total of 32 operators that together had 1.5 million SOL, about 0.5% of program stake, a source said.

"Enforcement actions are on going as we detect operators participating in mempools which allow sandwich attacks," a representative for the Solana Foundation said Sunday.

More For You

KuCoin Hits Record Market Share as 2025 Volumes Outpace Crypto Market

16:9 Image

KuCoin captured a record share of centralised exchange volume in 2025, with more than $1.25tn traded as its volumes grew faster than the wider crypto market.

What to know:

  • KuCoin recorded over $1.25 trillion in total trading volume in 2025, equivalent to an average of roughly $114 billion per month, marking its strongest year on record.
  • This performance translated into an all-time high share of centralised exchange volume, as KuCoin’s activity expanded faster than aggregate CEX volumes, which slowed during periods of lower market volatility.
  • Spot and derivatives volumes were evenly split, each exceeding $500 billion for the year, signalling broad-based usage rather than reliance on a single product line.
  • Altcoins accounted for the majority of trading activity, reinforcing KuCoin’s role as a primary liquidity venue beyond BTC and ETH at a time when majors saw more muted turnover.
  • Even as overall crypto volumes softened mid-year, KuCoin maintained elevated baseline activity, indicating structurally higher user engagement rather than short-lived volume spikes.

More For You

How the ultra-wealthy are using bitcoin to fund their yacht upgrades and Cannes trips

wealthtransfer

Cometh founder Jerome de Tychey is applying DeFi lending and borrowing on platforms like Aave, Morpho, and Uniswap to structures that help the ultra-wealthy secure loans against their massive crypto fortunes.

What to know:

  • Wealthy investors who hold much of their fortune in crypto are increasingly turning to decentralized finance platforms to secure flexible credit lines without selling their digital assets.
  • Firms like Cometh help family offices and other rich clients navigate complex DeFi tools, using assets such as bitcoin, ether and stablecoins to replicate traditional Lombard-style collateralized loans.
  • DeFi loans can be faster and more anonymous than traditional bank credit but carry volatility and liquidation risks, and Cometh is also experimenting with applying DeFi strategies to traditional securities via ISIN-based tokenization.