What happened

Shares of aluminum maker Constellium N.V. (CSTM -0.43%) jumped as much as 18.7% in trading Friday after rumors began swirling the company could be bought out. At 3:30 p.m. EDT shares were trading up 17.1% on the day.

So what

Bloomberg reported today that Constellium has gotten buyout interest from unnamed companies. According to Credit Suisse analysts, the company could be worth $16 to $18 per share, about double what shares were worth at the close of the market Thursday.

Molten aluminum being poured into a mold

Image source: Getty Images.

There's nothing more than reports and rumors right now, but watch to see if management addresses these reports over the weekend -- that could give them credence, or leave them in the unconfirmed rumor mill.

Now what

Buying on a rumor is risky, and that's what will keep me out of the stock today. But Constellium is in a good market serving aerospace customers, and with shares trading at about 10 times forward estimates there could be value for buyers. But don't be surprised if the stock falls if management says they aren't considering an offer, because all that's driving the stock higher today is rumors.