Frenzied retail buying catapults equity benchmarks to records. A handful of mega-companies dominate, drawing daily warnings about nosebleed valuations. Suddenly a rotation takes hold, reviving left-behind industries while crushing the broader market. The 2021 setup in stocks? Maybe. They are the same circumstances investors faced two decades ago, when the popping of the dot-com bubble unleashed a protracted swoon in the S&P 500 and Nasdaq 100. A less-discussed aspect of that episode is that it became a good time for stock-picking hedge funds, whose ability to navigate three years of volatility could be a blueprint for success today.