Ethereum's validator exit queue is public, deterministic, and slow. When a large entity starts withdrawing, you know — to the epoch — when their stake will land on-chain. That predictability is mostly a feature. But it has an edge: anyone who knows exactly when tens of thousands of ETH will hit the market can position ahead of it.
On May 7, 2025, Ethereum's Pectra upgrade (fork name: Electra) activated EIP-7251 — the Maximum Effective Balance change. The idea was to let validators hold up to 2,048 ETH each, unlocking two things: compounding rewards for validators who opt in, and simpler operations for large stakers who no longer need to manage thousands of 32-ETH keys.
Most coverage focused on the compounding angle. The real story turned out to be something else.
In the nine months since Pectra, Ethereum's active validator set has shrunk by 110,007 validators — from 1,068,860 to 958,853. Meanwhile, 3,055 mega-validators holding more than 1,024 ETH each have emerged from essentially nowhere.
One validator missing an attestation isn't a crisis. A few hundred validators missing 1 in 8 attestations, every slot, for three months straight — that's a different story. And it's concentrated in a way that the aggregate participation numbers don't show.
The xatu dataset tracks missed attestations at the entity level. When you sort by miss rate, a clear hierarchy emerges — and a handful of operators sit far outside the expected range.