York Space Systems Inc. (NYSE:YSS – Get Free Report) major shareholder Blackrock Portfolio Management sold 13,754 shares of the company’s stock in a transaction on Monday, August 3rd. Blackrock Portfolio Management also recently made the following trade(s):Get York Space Systems alerts:On Friday, July 31st, Blackrock Portfolio Management sold 35,574 shares of York Space Systems stock. On Thursday, July 30th, Blackrock Portfolio Management sold 140,823 shares of York Space Systems stock. On Wednesday, July 29th, Blackrock Portfolio Management sold 63,390 shares of York Space Systems stock. See AlsoReceive News & Ratings for York Space Systems Daily - Enter your email address below to receive a concise daily summary of the latest news and analysts' ratings for York Space Systems and related companies with MarketBeat.com's FREE daily email newsletter.