Short Seller Culper Shorts Ether and BitMine, Questions Ethereum Upgrade’s Impact on Token Economics

Ethereum completed its Fusaka upgrade in December 2025, expanding block space to reduce transaction costs. However, fees also determine how much ETH is burned and how much validators earn. A prolonged decline in revenue could weaken staking incentives and the token’s scarcity. BitMine has bought ETH aggressively since July 2025, leaving its shares closely tied to the cryptocurrency’s price.

Culper Research disclosed short positions in ETH and related securities, including BitMine (BMNR), on March 5, 2026. It said fees had plunged about 90% since Fusaka and that dusting wallets accounted for 95% of growth in new wallets. The report said BitMine had accumulated about 4.4 million ETH, with a paper loss of roughly 45% and estimated unrealized losses of $7.4 billion, while staking yields continued to decline.