This week’s investor run on the FTX crypto-currency exchange marks round two of the great crypto crackup, and so far the victims are consenting adults. Barring an unexpected spread to the banking system, this is another in the long line of easy-money manias turned to panic.

FTX CEO Sam Bankman-Fried has been the crypto industry’s leading champion. This year he engineered bailouts of several troubled crypto firms, including lenders Voyager Digital and BlockFi Inc., as plunging digital asset values exposed bad bets and computer coding. Recall the May collapse of stablecoin TerraUSD, whose stable value was based on an algorithm.

Crypto markets have lost some $2 trillion in market value over the last year as the Federal Reserve has removed liquidity and markets reprice financial assets. Yet even as other crypto firms ran into trouble, Mr. Bankman-Fried insisted that FTX was solid. On Thursday he acknowledged in a Twitter mea culpa for the ages that he was wrong.