A bull market has a way of papering over investing mistakes that tougher times for equities lay painfully bare. Shortsightedness, overconfidence and -- most important -- failing to have a plan are more likely to hurt investors' long-term results than the inevitable ups and downs of stocks and bonds, says Jonathan Satovsky, chairman and chief executive of Satovsky Asset Management.

Failing to set forth clear long-term objectives, overestimating their own risk-tolerance and swapping investing strategies in mid-stream are just a few of the ways in which investors hurt their returns. "Too often people second-guess their plan when they are caught up in the minutiae of the market or a hot trend," Satovsky says. "What they don't realize is their plan is doing exactly what it is intended for -- producing superior returns over the long term."

The bottom line is that fear and greed are an investor's worst enemy. For more of Satovsky's insights into the most common investing mistakes, see the video below.