BitMEX, a cryptocurrency derivatives exchange, has launched an investigation into unusual activity after users reported a temporary drop in the price of Bitcoin on the platform. The incident occurred at around 1 am UTC, when users noticed an anomaly in BitMEX’s BTC/Tether spot market, causing Bitcoin prices to briefly plummet to around $8,900. It is believed that an unknown entity sold more than 400 BTC in a short period of time, prompting BitMEX to confirm the large sell order and initiate an internal investigation. BitMEX stated that its derivatives markets and the prices of XBT derivatives contracts were not affected by the fluctuation. Crypto researcher Syq revealed that the unknown whale sold batches of 10-50 BTC over a two-hour period and that BitMEX had blocked withdrawals from some accounts. BitMEX responded by assuring users that its trading platform is functioning normally and all funds are secure. The exchange has yet to comment on the incident in response to Cointelegraph’s request. Former BitMEX CEO Arthur Hayes has previously expressed concerns that spot Bitcoin exchange-traded funds (ETFs) could have a detrimental impact on Bitcoin, potentially leading to a decline in transactions on the network and a loss of mining incentives.