NEW YORK ( TheStreet) -- Plenty of investors are furious at their actively managed mutual funds. In recent years, many formerly hot managers have suddenly turned cold. Convinced that it is impossible to pick winning funds, shareholders are dumping old standbys and switching to index funds.But before you give up on veteran managers, consider that the period since the financial crisis has been unusually difficult for active funds. The problem has been that the markets have moved wildly. Strategies that worked one year failed miserably the next. During the turmoil of 2008, cautious funds with high-quality stocks led the pack. But in 2009, the best performers were shaky issues that rebounded from depressed levels. Because of the market shifts, managers who followed a consistent approach were bound to suffer periods of underperformance. According to an ongoing study by Standard & Poor's, the recent erratic record of funds is very different from other periods. During the early part of this decade, winning funds tended to continue producing above-average results. Of the domestic equity funds that finished in the top half of the group during the 12 months ending in May 2001, 78.7% repeated their showing by again delivering above-average results in 2002. Of the 2001 winners, 43% stayed in the top half for three years in a row. In contrast, funds that finished in the top half for the 12 months through March 2008 did much worse in succeeding years. Only 14% stayed in the top half for three years in a row and 5.2% stayed in the top half for five years in a row. The data should give heart to shareholders of active funds. In recent months, the markets have returned to normal levels of volatility. If that persists, active managers should deliver more consistent results and top funds could once again record long winning streaks. To find future stars, I looked for funds that had finished in the top half of their categories in each of the past five years. Such funds have proved that they are all-weather performers, able to limit losses in steep downturns and deliver decent results in better times.