Buffett lowers his holding in Bank of America from 13.1% to 10.1%, following significant gains since his initial investment in 2011.

The legendary investor has been reducing his 13-year-old stake in BofA. It's the most recent instance of Buffett profiting from a big bet on a troubled financial institution.

Buffett doesn't mind sharing his investment philosophy, and comments regularly about his commitment to quality companies over the long term and his general belief in these companies -- through both bull markets and bear markets.