Berkowitz, who once sat on the board of the ailing retailer, reported owning only 4,578,440 shares of the company, a position diminished from 14,061,947 shares he owned at last count on Aug. 28. The sale represents the largest decrease he has made in the position in at least the past nine years on record. At peak, his holding topped 28.9 million shares in the first quarter of 2017.