The world's largest bitcoin miner, Core Scientific (CORZ), warned that it may have to explore bankruptcy if it fails to improve its financial condition. The warning sent its shares down 77% to as low as 23 U.S. cents. The miner said it anticipates existing cash resources will be depleted by the end of the year, possibly sooner. "Substantial doubt exists about the company's ability to continue as a going concern for a reasonable period of time," it said in a filing Thursday. The miner is exploring a number of strategic alternatives for raising additional capital.