Shares of CommVault Systems Inc. CVLT, +11.89% shot up 11% in premarket trade, putting it on track to open at an eight-month high, after the company said activist investor Elliott Management disclosed a 10.3% stake in the data management company. That would make Elliott the largest shareholder, based on FactSet data. CommVault said Elliott, a hedge fund founded by billionaire investor Paul Singer, has nominated four people to join CommVault's board of directors. In a letter to CommVault's board, Elliott said it believes the company's current market value doesn't reflect its leadership in the data management software market. Elliott said it is looking forward to "constructive engagement" with the company to find a "mutually supported path forward" to create significant shareholder value. CommVault's stock has run up 7.9% over the past three months through Thursday, while the S&P 500 SPX, -1.20% has lost 2.0%.