British hedge fund manager Crispin Odey thinks we've entered an economic downturn that is "likely to be remembered in a hundred years," and central banks won't be able to stop it. In his Odey Asset Management investor letter dated Dec. 31, 2014, Odey writes that the shorting opportunity "looks as great as it was in 07/09." "My point is that we used all our monetary firepower to avoid the first downturn in 2007-09, so we are really at a dangerous point to try to counter the effects of a slowing China, falling commodities and EM incomes, and the ultimate First World Effects.