INVESTOR PULLOUT

Investors have not been pleased with the shift, pulling nearly $27 billion from funds that increased exposure to energy, according to Lipper data. Those which did not, saw about the same amount of net investor withdrawals, but over a larger number of funds with nearly five times more in assets, Lipper data shows.

BMO's Ramos said managers and investors have to remain patient with their energy picks.

"We think we will eventually be rewarded with these stocks," he said.

The $2 billion Ridgeworth Large Cap Value Equity Fund made among the biggest bets on the energy sector among its peers earlier this year, raising its exposure to 14 percent at the end of August from 6.7 percent at the end of February, according to Lipper. The fund nearly doubled its stake in ConocoPhillips and bought more shares in EOG Resources, Hess Corp and Noble Energy Inc, disclosures show.

All of those stocks are down at least 19 percent over the past three months, badly underperforming broad benchmarks.

The Ridgeworth fund's year-to-date total return of minus 13 percent is worse than 88 percent of similar funds, according to Morningstar Inc. Mills Riddick, manager of the fund, declined to comment for this story.

Other portfolio managers who bet big on some energy stocks, thinking they found bottom, or somewhere near it, have been sorely disappointed, too.

Take the $68 billion Investment Company of America fund , which bought nearly 23 million shares of former shale oil boom star Chesapeake Energy Corp during the first half of the year. That represented just 0.50 percent of the fund's assets, but still hurt as Chesapeake shares dropped 43 percent during that time. Chesapeake stock has fallen 70 percent since November, and 39 percent since June, to below $7 a share.

The fund, run by Capital Group's American Funds, declined to comment, saying as a matter of policy the company does not discuss individual holdings. The fund's year-to-date total return of minus 8.90 percent is worse than that of 66 percent of peers, according to Lipper. The fund is not alone as many other managers have made bets on the belief that the slump in oil prices would be short-lived.