I would be hesitant to assume that this is a great deal, because this is a situation where insiders will have a lot better knowledge than retail investors. People on Wall Street will know the details of Nasdaq's situation and why this deal might not go through. In this particular situation, I think the market has probably priced the target efficiently.

As for the acquiring price being lower than the previous market price, what probably happened is that the target company had been bid up significantly on rumors of an acquisition. Nasdaq is still paying a premium to the true value of the target, it's just that that premium had already been incorporated into the price.

I'm in a similar situation with Reebok, which is being bought by Adidas. The offer price is $59, and RBK is trading around $57. This discount is largely based on the cost of money. I don't think this is a particularly good opportunity either, I just haven't found anywhere else to put my money.