Billy Markus, co-creator of Dogecoin, has criticized the excessive optimism surrounding 'Uptober' as the cryptocurrency market experiences a significant downturn. Markus, known as Shibetoshi Nakamoto, attributed the market crash to misplaced enthusiasm and speculative leverage. The downturn was exacerbated by new U.S. tariffs and export controls on China, leading to a 12% drop in Bitcoin and the liquidation of $19 billion in leveraged positions within 24 hours. Dogecoin saw a 26% decline, marking one of its steepest drops this year. Despite the market turmoil, some analysts remain optimistic about a potential rebound.