A whale identified as 'Penision Fund' has opened a significant short position of 10,000 ETH with 2x leverage as Ethereum's price surpassed $4,200 on October 15, 2025. This move involves over $41 million, despite the whale incurring a $3.41 million loss from previous long trades. Known for targeting key Ethereum price levels, the whale typically maintains positions for around seven hours and has been actively trading since transferring $30 million three days ago.