Genco Shipping & Trading (GNK) saw a significant 6.8% surge in after-hours trading, reaching $25.76, as activist investor Diana Shipping Inc. continues its campaign and Genco's board reviews a revised buyout offer. Diana Shipping, GNK's largest shareholder, made a revised non-binding offer valued at $27.34 per share, consisting of cash and Diana shares, despite losing a June 18 board vote. This after-hours jump follows a volatile period, including a 5.4% surge on June 23 and a 2.9% pullback on June 24.