In a regulatory filing, Joly said he exercised some 350,467 stock options at $18.02 a share, for a total of about $6.3 million.
He then sold those shares, plus other holdings in the consumer electronics chain, for a total of 451,153 shares for $16.7 million.
That means he made about $10.4 million from the sale.
Best Buy Co. (BBY) said in a statement that Joly sold the stock "due to circumstances related to his marital dissolution." The chain said that he still owns stock that is substantially more than the 140,000 share ownership target that is part of its executive stock ownership guidelines.
Last month, Best Buy reported second-quarter results that topped analyst estimates as it slashed costs and worked to make its website more competitive. The retailer has been shuttering underperforming stores and revamping others to offset tough competition from discounters and online retailers.
Under Joly, who took the helm of the company a year ago, Best Buy has instituted a price-matching policy, opened more in-store areas for manufacturers such as Apple (AAPL) and Samsung, and invested more to train employees.
Shares of Best Buy added 5 cents to $37.97 in afternoon trading. Earlier in the session, the stock hit $38, its highest point since December 2010. The stock has more than tripled since the start of the year.