Law firm may put the brakes on Avis-Zipcar deal for undervaluing stock

News that Avis Budget Group plans to buy top car sharing network Zipcar for $500 million opened some eyes this morning. But the deal could have some trouble going through, with a law firm announcing it is investigating whether Zipcar didn't get the best deal possible.

Groupon investigated for odd stock spike prior to earnings report

Groupon is being investigated by the Financial Industry Regulatory Authority after the company’s stock made a sharp, upward turn Monday, before earnings beating expectations were delivered at the close of business that same day.

Finra, which watches for oddities within …