1932!
From Bespoke Investment Group:
Man, this is getting ugly. If the month were to end today, the Dow would be down 10.30% this June. That would mark the worst June for the Dow since 1930, and the worst month for the index since September 2002 (-12.37%). Unfortunately, the month still has one more day next Monday....MORE
After that July 8,1932 closing low of 41.22, the Dow put on a nifty little seven week sprint to an intraday high of 77.01 on August 29. That 87% move might be the largest ever for a major index.
Of course very few people called the bottom with the notable exception of Robert Rhea:
...The next great Dow theorist, Robert Rhea, initially stumbled upon the Dow Theory during his endeavor to find "a system" for helping him make money in the stock market. In his attempts to disprove the theory, he became a convert. Rhea was a very serious student, and he was able to utilize the Dow Theory as interpreted by Hamilton to his advantage, buying and holding stocks in 1921, and basically holding them until late 1928 (he reversed his short position when he realized Hamilton's advice was incorrect in early 1926), missing only the final blowoff phase. He also "played" the short side successfully during the subsequent deflation. In 1932, he began publishing his newsletter based on the Dow Theory, called the "Dow Theory Comment."
Rhea called the bottom of the stock market in July 1932 almost to the exact day and the subsequent top in 1937. On July 21, 1932, with the Industrials at 46.50 and the Rails at 16.76, Rhea instructed his broker to tell his friends "the Dow Theory implied heavy buying for the first time in over three years." Further, on July 25, 1932, Rhea sent a memo to 50 correspondents, part of which is reproduced below:...
