Shares of Herbalife Ltd. rallied 1.1% in premarket trade Wednesday, after the nutrition company said it commenced a self-tender offer to buy back up to $600 million worth of its shares. The company said it will not pay greater than $108.00 a share, which would be 4.8% above Tuesday’s closing price of $103.02, or less than $98.00 a share, which is 4.9% below. The tender offer is scheduled to expire on May 16, at 5:00 p.m. ET, barring an extension. “The company believes that the repurchase of shares pursuant to the tender offer is consistent with its long-term goal of maximizing shareholder value,” Herbalife said in a statement. The stock has soared 52% year to date through Tuesday, while the S&P 500 has gained 1.2%.