Tilson recently made a 180-degree turn on Lumber Liquidators Holdings Inc $LL, one of his most famously successful short calls several years ago. Tilson is now a Lumber Liquidators bull. “It’s a great case study of one of the most important things you must be able to do as an investor, which is keep an open mind and be willing to accept disconfirming information and be willing to either admit that you were wrong or simply say this story has played out and it’s time to take my profits,” Tilson said.