Although we don't believe in timing the market or panicking over market movements, we do like to keep an eye on big changes -- just in case they're material to our investing thesis.

What: Shares of warehouse club operator BJ's Wholesale Club (NYSE: BJ) rung up more than 11% in intraday trading on news that the company has put itself up for sale.

So what: A buyout offer from private equity firm Leonard Green & Partners pushed BJ's to hire Morgan Stanley (NYSE: MS) to run an auction process for the company. As with most buyouts, it's unlikely that any would-be acquirer would be able to snap up the company without paying a premium over the current share price, thus the pep in the company's shares today. BJ's is a good fit for Leonard Green as its retail-focused portfolio includes companies such as Petco, Whole Foods (Nasdaq: WFMI), The Container Store, and Rite Aid (NYSE: RAD). However, private equity firms have begun opening their wallets again, so it wouldn't be too surprising to see some competition for the deal.

Now what: Speculating on a takeover can be tricky business, so most investors should be buying right now only if they like the business and the valuation and would be OK holding the stock if the buyout scenario falls apart. If you've got a hankering for warehouse club exposure and don't want to chase BJ's and its buyout hoopla, you could also consider Costco (Nasdaq: COST) or Sam's Club owner Wal-Mart (NYSE: WMT).

Want to keep up to date on BJ's? Add it to your watchlist by clicking here.

Costco Wholesale and Wal-Mart Stores are Motley Fool Inside Value picks. Costco Wholesale and Whole Foods Market are Motley Fool Stock Advisor recommendations. Wal-Mart Stores is a Motley Fool Global Gains choice. The Fool owns shares of Costco Wholesale and Wal-Mart Stores. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors.

Fool contributor Matt Koppenheffer owns shares of Wal-Mart, but does not own shares of any of the other companies mentioned. You can check out what Matt is keeping an eye on by visiting his CAPS portfolio, or you can follow Matt on Twitter @KoppTheFool or on his RSS feed. The Fool's disclosure policy assures you no Wookiees were harmed in the making of this article.