Traders, especially of the mom-and-pop variety, have the tendency to cling to losing positions while taking profits in the winners. Chalk it up to human nature — and the market axioms that are constantly pounded into their heads.

“Pigs get slaughtered” comes to mind.

But Jon Boorman, a portfolio manager at Broadsword Capital, LLC, says that approach often proves costly when it comes to managing your portfolio.