Investors considering buying shares of ( FCNTX) Fidelity Contrafund better hurry up and get their orders in, because the mega-fund is closing its doors to new accounts later this month. Fund giant Fidelity announced today that it is closing both the popular Contrafund and its ( FNIAX) Fidelity Advisor New Insights fund to new investors on April 28 because of overwhelming inflows over the past 12 months. New purchases in the funds will be limited to existing shareholders after that date. Will Danoff is the portfolio manager of both of the large-cap stock funds and has led the Contrafund to market-beating returns since 1990. The New Insights fund was launched in the summer of 2003. Contrafund is up 4.9% year to date, according to fund tracker Morningstar, 44 basis points better than the benchmark S&P 500. Danoff has guided Contrafund to average gains of 22% annually over the past three years and 10.3% over the past five years, both returns substantially outperforming their bogey. Despite the fund's impressive outperformance, analysts and investors have long worried that the Contrafund would grow too large for Danoff to successfully steer. At last check, Contrafund held just under $64 billion in assets, surpassing ( FMAGX) Magellan as Fidelity's largest fund. When a fund's asset base grows too large, the phenomenon is referred to as "asset bloat," and it can make it more difficult for portfolio managers to get in and out of their stock positions, even in large liquid names such as the ones Danoff was trading. Morningstar analysts have been clamoring for months that Fidelity would best serve its shareholders by shutting the fund to new investors. Apparently, the fund giant has decided to listen. Fidelity says investor inflows into the two funds accelerated in the past 12 months to the tune of $12 billion in net new cash. "We believe that closing Contrafund and Advisor New Insights at this time is in the best interest of the funds' shareholders, and stabilizing cash flows will help provide Will with the opportunity to maintain the funds' consistent performance track records," the firm said.