Nvidia gave up on buying arm and Lockheed is having issues buying Aerojet-Rocketdyne. They aren't 1 to 1 comparisons, just high profile examples from a couple days ago.
Nvidia preparing to abandon Arm takeover, Bloomberg reports
FTC Sues to Block Lockheed Martin Corporation's $4.4 Billion Vertical Acquisition of Aerojet Rocketdyne Holdings Inc. | Federal Trade Commission