The company said Thursday that it is evaluating its strategic options and has hired Morgan Stanley & Co. as its financial adviser.
Its stock jumped $5.46, or 12.7 percent percent, to $48.47 in morning trading.
BJ's, based in Westborough, Mass., has been rumored as a possible takeover target since July, when Leonard Green & Partners LP bought a 9.5 percent stake. The Los Angeles private equity firm has reportedly expressed interest in purchasing the company.
Leonard Green & Partners is not new to retail buyouts, announcing in December that it would buy fabric and craft store chain Jo-Ann Stores Inc. for about $1.6 billion. It is also involved in the $3 billion deal for J. Crew Group Inc.
Some analysts have supported a BJ's acquisition, saying it would likely help the regional warehouse club operator expand nationally.
BJ's said it has not made a decision to pursue any specific deal or other strategic option. There is no guarantee the company's evaluation process will result in a sale and no timetable has been set for the process.
BJ's, which has 189 warehouse clubs in 15 states, announced last month that it was closing five stores and cutting nearly 500 jobs.
It also said that Chief Financial Officer Frank Forward would retire, a switch that has been under discussion since 2007. He will be replaced by Robert W. Eddy, BJ's director of finance.