John C. Bogle The Little Book of Common Sense Investing: The Only Way to Guarantee Your Fair Share of Stock Market Returns

Investing is all about common sense. Owning a diversified portfolio of stocks and holding it for the long term is a winner's game. Trying to beat the stock market is theoretically a zero-sum game (for every winner, there must be a loser), but after the substantial costs of investing are deducted, it becomes a loser's game.