Legg Mason legend Bill Miller’s exodus is a blip in the road for all mutual fund managers struggling with the new era of tough markets.

Mutual fund giant Legg Mason recently announced the departure of Bill Miller, portfolio manager of the Legg Mason Capital Management Value Trust after a five year period of poor performance.

Miller, famously known for his record 15 year winning streak beating the Standard & Poor’s 500 Index from 1991 to 2005, made a bullish bet on financial stocks at the height of the credit crisis in 2008, according to Bloomberg. He has not seemed to recover since then; Value Trust trailed benchmarks with a modest gain of 6.7% in 2009, and is down 5.5% this year.

All winning managers eventually step down and for some; Miller’s case is not that unusual.

“When he finishes his tenure on Value Trust, it will be April 2012 and he will have spent 30 years on the fund–certainly a long tenure! The transition to Sam Peters thus finishes a transition to successor that was started several years ago,” said Bridget Hughes, associate director of fund analysis at Morningstar.

Peters joined Legg Mason in 2005, and is formerly of Fidelity Investments. Miller will remain as portfolio manager on Legg Mason Capital Management Opportunity Trust, and remain Legg Mason Capital Management’s Chairman.

“I wouldn’t say that Miller is stepping off the fund because of weak performance,” Hughes continued. “That said, he did step announce stepping back after the fund has experienced a particularly weak five-year period– so bad, that Miller’s previously superior performance advantage has been largely wiped out.”

According to Morningstar data, the period between 1991 and the end of October 2011, Value Trust still beat the S&P 500 Index, but only about 40 basis points; a measly number that compares with a 500 basis point premium at the end of 2005, the last year of Miller’s famous 15-year streak of beating the S&P 500 Index.

Miller isn’t the only one that has had its share of troubles in the past five years, Hughes wrote Markets Media.

“In particular 2008, 2010, and 2011 have been volatile at best, but also destructive when it comes to the global equity markets (for the most part). Investors have responded as they always have–by moving away from stocks and into bonds. Another wrinkle in the fund-flows story has been the introduction of target-date funds, which have been popular. These funds tend to include a mix of stocks and bonds.”

Morningstar named Bill Miller U.S. Equity Fund Manager of the Year in 1998. Legg Mason could not be reached for comment by press time.