A trader or entity holding an extremely large position in a cryptocurrency or asset who actively uses that size to push prices lower, combining the concepts of a bear (one who profits from declining prices) and a whale (a holder with enough capital to move markets). The term gained widespread usage in the Bitcoin community after a famous 2014 incident in which a single seller placed a 30,000 BTC sell order on Bitstamp at $300 per coin. BearWhale events highlight the outsized influence that concentrated holders can exert on relatively illiquid markets.
Example
“The community rallied to absorb the BearWhale's massive sell order on Bitstamp, and within hours the entire 30,000 BTC wall had been eaten through by eager buyers.”