Bitmine is the largest Ethereum treasury company, holding 3.5 million ETH, followed by Sharlink (860,000 ETH) and Ether Machine (496,000 ETH).
"Bitmine, which holds over 3.5 million ETH. Trailing in second place is Sharlink with just over 860,000 ETH, followed by Ether Machine with 496,000 ETH."