Dealmakers are suddenly busy again, as consolidation in the energy patch helped make this one of the busiest months in years for US mergers and acquisitions. 

Corporate chieftains are pushing ahead with major deals even as geopolitical uncertainty worsens and the market digests the escalating Israel-Hamas war. On Monday, Chevron Corp. announced a $53 billion acquisition of Hess Corp. to double down on fossil fuels, while Vista Equity Partners agreed to buy software company EngageSmart Inc. in a $4 billion deal.

More than $139 billion in takeovers of publicly traded US companies have now been announced in October, according to data compiled by Bloomberg. That’s roughly triple the same period last year and marks the highest volume for any single month since June 2019. Four of the five biggest M&A deals globally this year have been announced in the last two months. 

There’s been plenty of activity elsewhere as well, with Swiss drugmaker Roche Holding AG announcing Monday it will pay $7.1 billion for an inflammatory bowel disease treatment. Meanwhile, tycoon Mukesh Ambani’s Reliance Industries Ltd. is moving closer to a multibillion-dollar deal for Walt Disney Co.’s Indian operations, Bloomberg News reported Monday. 

Microsoft Corp. completed its $69 billion purchase of Activision Blizzard Inc. this month following a nearly two-year regulatory battle, potentially giving confidence to other companies they can win the day against antitrust authorities.

The year’s largest transaction, Exxon Mobil Corp.’s $60 billion takeover of Pioneer Natural Resources Co., came less than two weeks ago. More deals could be in the works, with Devon Energy Corp. studying major acquisition targets including Marathon Oil Corp. to help it gain scale in US shale, people with knowledge of the matter have said. 

Drugmakers have also been active, with Bristol Myers Squibb Co. agreeing this month to buy biotech firm Mirati Therapeutics Inc. to replenish its pipeline.

Goldman Sachs Group Inc. has grabbed the top spot as the most active M&A adviser globally so far this year with a 26% market share, according to data compiled by Bloomberg. They’re followed by Morgan Stanley with 22%, while JPMorgan Chase & Co. ranks third with 21%.