I remember reading a story of a trader who averaged down on Russian bonds and ended up losing $100mm+ or something like that because they thought the outcome an impossibility. Racking my brain but I can't think of who it was. Maybe it wasn't the 90s.
You guys both jogged my memory. It wasn't Victor, but Victor's wiki page references Fooled By Randomness which has the story I'm thinking of. Taleb talks about a guy "Carlos the Emerging Markets Wizard" who seems to be a guy from LTCM