An index linked to Bitfinex and tracking Ether short positions reached approximately 73,056 ETH on Sept. 24, the highest level in 51 months. The reading marked a roughly 280% increase from the previous week and represented nearly $195 million in exposure at prices cited in the report. The buildup came as ETH gained about 10% over seven days, recovered approximately 86% from a mid-year low near $1,506 and traded around $2,670; another cited price was $2,652. At the same time, large-scale holders accumulated hundreds of millions of dollars worth of ETH. Margin data cannot determine whether traders are making outright bearish bets or hedging spot holdings. If ETH continues higher, margin calls could force short sellers to buy back positions, creating a short squeeze.