Many investors are abandoning actively managed funds, wary of their high fees and recently disappointing performance. [...] they're funneling money into lower-cost index funds, which aim to match the stock market's returns rather than beat them. Bill Miller, for example, became famous for guiding his fund at Legg Mason to better returns than the Standard & Poor's 500 index for 15 straight years. There can be a wide discrepancy among the performance of various foreign markets, which makes it even more worthwhile to stick with winners and avoid losers. [...] simply avoiding Japanese stocks was a good way for global fund managers to beat their benchmark during that period. For all the criticism heaped upon fund managers, many beat their benchmark index. Exxon Mobil has shed 11 percent of its value due to the plunge in the price of crude oil. Fund managers who own a mix of value and growth large-cap stocks keep much less of their portfolios in Exxon Mobil than the S&P 500, according to a review by Goldman Sachs. [...] it's the least-owned stock, relative to its weight in the index.