This week's mega-deal was the announced $74 billion acquisition of Celgene by Bristol-Myers Squibb. BMS is paying one share of its own stock, plus $50 in cash, for each share of Celgene, which works out to about $68 billion at current prices. The combined company looks to be worth on the order of $150 billion, making it the 6th-largest pharmaceutical company in the world.
The big picture: Pharmaceutical mega-mergers are common. (Wikipedia has an exhaustive list.) Pfizer, in particular, is a product of M&A, having bought Pharmacia, Wyeth and Warner-Lambert in deals worth a combined $244 billion. Meanwhile, technology mega-mergers are rare, with the disastrous exception of AOL-Time Warner.