From Micheal Burry´s 4Q2000 Annual Letter:
When planning for a double, every dollar in excess cost amounts to two dollars in excess gain required. Every dollar saved amounts to the same two dollars in excess gain already realized. And it goes without saying that a 33.3% loss requires a 50% gain just to attain breakeven. On the flip side, 33.3% saved on the buy price makes a 50% gain back to the price of first consideration. On a percentage basis – and it is on this basis that we must evaluate each and every decision – lost dollars are simply harder to replace than gained dollars are to lose.