Jeff Bezos, Jay Powell, Serena Williams and More Will Speak at the DealBook Summit

Mr. Griffin, who had previously derided Donald J. Trump as a “three-time loser,” said he voted for the president-elect.

Nearly 10 years after buying Family Dollar for about $9 billion, Dollar Tree announced it would sell the retailer to two private equity firms.

Howard Lutnick, co-chair of the president-elect’s transition team and a Wall Street financier, is leading the search for appointees while still running his businesses.