Adam Thurgood, managing director and partner at HighTower Advisors Las Vegas, says that investors shouldn't be shaken from diversification and other measures just because it looks like it's not working when the market has a terrible day. Even gold moved down big in the market's huge drop on March 9, he notes, but precious metals -- as well as high-quality corporate bonds and other safe havens and diversifiers -- did their job and held up well over the market's entire 20 percent drop from a high on February 12 through the March plunge. You're not defending against a bad day, Thurgood noted, but against bad conditions long-term.