Morrisons confirmed David Potts had bought 508,000 shares at 205.85p per share.
Mr Potts, who replaced Dalton Philips as boss of the supermarket, has been tasked with turning the company around as profits dropped to their lowest in eight years.
In the days since taking his post on Monday, the former Tesco executive Potts launched an appeal for customers to tell him what they want from the supermarket.
He also urged management to go back to the shop floor in an effort to understand what shoppers need and the challenges the retailer is grappling with.
Earlier this month, Morrisons reported a £792m loss, after market conditions led to £1.3m in property write-downs and a 52 per cent drop in underlying profit.