Marathon Digital Holdings' (NASDAQ:MARA) Executive Chairman Merrick Okamoto plans to retire at the end of this year, with CEO Fred Thiel succeeding Okamoto on Jan. 1, 2022. Prior to his role as executive chairman, Okamoto joined MARA in 2017 as the company's chairman and CEO. In April of this year, Thiel replaced Okamoto as CEO, as part of a succession plan. The company is now evaluating candidates to fill Okamoto's vacancy on its board of directors, it says. Meanwhile, shares of MARA gain 1.9% in after-hours trading. Previously, (Nov. 18) Marathon Digital's CEO believes crypto regulation "levels the playing field."