On June 25, the amount of Bitcoin (BTC) margin shorts at Bitfinex increased by 22,000, equivalent to $726 million. At the time, Cointelegraph reported that there was a significant increase in Bitfinex's spot volume market share starting at 9 am UTC, matching the demand in the short margin.
Data confirms that one (or more) whales actively shorted the market, betting on a price decrease. The average price of the trade was around $33,000, so every $500 difference would result in an $11 million profit or loss when closing the short position.