The suggestion that your returns will be improved by timing the market correctly is reminiscent of Mark Twain's advice: "Buy good quality common stocks and hold 'em until they go up. If they don't go up, don't buy 'em."
Without a crystal ball, most investors will diminish their returns by
market timing. Legendary
fund manager Peter Lynch has pointed out how quickly
bull markets take hold and how easy it is to miss the early gains, which make the difference between success and mediocrity. As such, failure to perfectly time the market will more often than not result in an investor dragging his or her
portfolio down to levels below what it would have been if market timing had simply been avoided altogether.