No. 4: T. Rowe Price
Total mutual fund assets: $582.9 billion
Long-term assets: $566.2 billion
Founded by growth-stock pioneer T. Rowe Price, the Baltimore fund complex has become a stalwart no-load fund company, offering brokerage and advice to its lineup of funds. Still largely a growth shop — its largest fund remains the $51.2 billion T. Rowe Price Growth Stock (PRGFX) fund — T. Rowe has expanded aggressively into international and fixed-income investments.