knightswift transportation holdings inc on monday said its board approved the repurchase of up to 350 million of the companys common stock the phoenix trucking company which had about 1662 million shares outstanding as of feb 15 sports a market capitalization of roughly 78 billion based on fridays closing price of 4783 knightswift said a previous 250 million buyback that the board approved in late 2020 is terminated under that program the company bought back about 42 million shares for 2072 million including 28 million shares for nearly 150 million this year