Short version: Creditors want to assure the deal is approved, so they are buying shares in order to vote them.
Hedging the Bear Stearns Deal - Mergers, Acquisitions, Venture Capital, Hedge Funds -- DealBook - New York Times:
"The creditor buys Bear shares and a put at the price. Creditor then sells a call to pay for most (but probably not all) of the put. Creditor waits for the record date of the Bear shareholder vote so it can vote. It votes yes. Immediately thereafter the creditor sells its shares.
For a small sum (hedge) the creditor has now done its part to help the Bear deal go through despite the protests of Bear’s shareholders. And the creditor receives 100 cents on the dollar assuming JPMorgan makes good on the creditor’s debts.
Is this possible? It is not only possible, according to market reports, this is what is occurring and why Bear’s shares are trading at $6 a share."