Mutual Shares is closing its doors to new investors, making it the second large stock mutual fund to do so in two weeks. Last week the second-largest equity mutual fund, Vanguard Group's Windsor Fund, announced it would stop taking money from new investors because it could not find enough bargains in which to invest. Mutual Shares, known for buying cheap, out-of-favor stocks and bonds, has been getting too much money in recent months and cannot invest it according to its "buy cheap" philosophy, says fund manager Michael Price. So Mutual Shares, with $3 billion in assets, and a sister fund, Mutual Qualified Income, with $1.3 billion in assets, will stop accepting new accounts on June 1. Another fund in the same family, Mutual Beacon fund, will continue accepting new accounts; however, the minimum account it accepts is $50,000.