Our No. 1 stock for the rare "millionaire window" opening NOW According to Wall Street legend Whitney Tilson, an extremely rare window in the markets is about to open. It's an often-misunderstood market setup we've only seen 13 times since 1920. The last time this happened, it minted a million brand-new millionaires – in a single year. But Tilson says this unique window in the markets could close much sooner than anyone realizes, leaving most investors in the dust, while making a select few incredibly rich.