In fact, the odds are very good that stocks will do at least as well in the next 15 years as they did in the last 15. The S&P 500 currently pays a dividend yield of 2.2%. So stocks only have to achieve very modest capital gains in order to produce total returns in excess of 4%. When you are comparing funds, keep in mind the importance of reviewing returns from many time periods. To appreciate why, consider two large growth funds, Hartford Growth Opportunity ( HGOAX), which returned 10.8% annually during the past 10 years, and Jensen Quality Growth ( JENSX), with a return of 6.3%. At first glance, you may prefer the top performer. But the picture is very different when you consider that Jensen returned 2.4% annually during the past five years, and Hartford lost 1.1% during that time. The reason for the gap is that the two funds follow very different strategies. Jensen is an extremely cautious fund. The portfolio managers only take the highest-quality companies that have delivered high returns on equity for 10 consecutive years. Such stocks excel in downturns, when investors become nervous and seek security. The solid holdings enabled Jensen to outdo 98% of its peers during the turmoil of 2008. That helped the fund shine during the past five years. But the blue chips tend to lag during roaring bull markets when investors have enough confidence to bet that shaky companies will rebound. As a result Jensen trailed competitors during the rally that swept up stocks from 2003 through 2007. That showing hurt 10-year returns. Hartford follows a much more aggressive approach, loading up on fast-growing technology shares and sometimes taking volatile mid-cap stocks. The formula enabled the fund to soar earlier in the decade. But the strategy caused big losses in 2008 and pulled down 5-year returns. Which fund should you take? Either Hartford or Jensen makes a sound choice for investors who understand their approaches. But before you make any decision, you should recognize how the funds have performed under different conditions and in a variety of time periods. At the time of publication the author held no positions in any of the stocks mentioned.Follow @StanLuxenbergThis article is commentary by an independent contributor, separate from TheStreet's regular news coverage.