Regulation would likely dictate thorough investigation but I know of one example where it didn't happen: RBS purchase of ABN Amro circa 2008. I was at RBS at t

Regulation would likely dictate thorough investigation but I know of one example where it didn't happen: RBS purchase of ABN Amro circa 2008. I was at RBS at the time and I remember the fallout later when they realised that paying £10Bn in cash for ABN was a total disaster. I believe the term that was used was "due-diligence lite" to refer to the amount of investigation performed. Which was especially stupid given that, I believe, Barclays had already walked away from the deal.