What: Shares of large-crane maker Terex Corporation (NYSE:TEX) jumped 11% on an unsolicited takeover bid.

So what: Terex's management confirmed that it has received a buyout offer from Zoomlion Heavy Industry Science and Technology Co., known as Zoomlion, in China. The offer is for $30 per share in cash, which is a large premium from the share offer that the company has agreed to from Konecranes

Terex has reportedly been fending off a bid from Zoomlion for some time now, and that's why the company went public with its unsolicited bid. It's not clear what the cost would be to get out of its deal with Terex, but the board has to consider it, considering the huge premium Zoomlion is offering.

Now what: There are a lot of unknowns with the offer today. Konecranes has already put out a statement questioning whether Zoomlion has the ability to pull off such a merger. And Terex's management has said that it wants to go forward with the current Konecranes deal.

That puts investors in a tough position given the lower value of the Konecranes offer, and I would take today's pop with some skepticism considering the possibility that Zoomlion is rebuffed again. But if the offer is accepted, the stock has a lot of upside potential, so it might be worth holding onto today.