CNBC is reporting that Mick McGuire has sent a letter to Sotheby’s lead director Domenico DeSole demanding a stock buyback of $500m worth of shares, a new CFO and accuses them of willful neglect and misguided policies. This letter comes shortly after Sotheby’s announced it would not continue with its capital plan until a new CEO is selected.

The letter puts McGuire who owns a bit more than 7% of the stock at odds with Dan Loeb who sits on the board. There has also been an influx of new institutional money since it was announced the CEO Ruprecht would step down.

“Despite our dialogue with you and other members of the board, a substantial portion of Sotheby’s invested capital continues to earn a poor return or worse yet, earns no return at all,” wrote Mick McGuire, founder of the $3 billion San Francisco fund company, in his Feb. 20 letter to lead independent director Dominico De Sole. “This willful neglect on the part of both management and the Finance Committee of the board must end urgently.”

Hedge fund Marcato rips into this swanky auction house Sotheby’s.