Traders in the 30-year bond options pit watch televisions showing Federal Chairman Ben Bernanke's news conference at the CME Group in Chicago on April 27, 2011. - 

Jeremy Hobson: In Illinois, state lawmakers have rejected a bill that would have offered millions of dollars in tax breaks to keep the Chicago Mercantile Exchange from leaving the state. So what happens now?

Here's Susie An from WBEZ in Chicago.

Susie An: The CME Group has been at the center of Chicago's financial sector for more than 160 years.

Gaston Ceron is an equity analyst with Morningstar.

Gaston Ceron: Chicago has taken on a much more visible role because of the tremendous growth we've seen in derivatives trading, for which Chicago has been a hub.

But now CME is threatening to leave Chicago because of a recent hike in the Illinois corporate tax rate. But a move wouldn't be cheap.

Stacey Kruger Birndorf is with the commercial real estate firm Transwestern. She says just relocating its computers and electronics could cost millions. CME employs as many as 2,000, but many other jobs in Chicago rely on it.

Stacey Kruger Birndorf: There are these other companies that are affiliated with them, and what about them?

And then there's what to do about the big Chicago Board of Trade building that it owns.

Kruger Birndorf: I'm seeing right outside my window right now. I can see the goddess of Ceres there, and she's not going to be moved. That whole building's going to have to stay there.

The CME Group wouldn't comment on what it'll do next.

In Chicago, I'm Susie An for Marketplace.