OK, I understand this now. I was one of those people who toned down my position when I was told in the press that he had exited. It made no sense to me that he would do that, but that is how it was reported. Oh well, I still own a good position so I'm happy to see him buying more.
CNBC reporting that Berkshire Hathaway's latest quarterly disclosure shows a new position in DE. Berkshire had been in earlier and sold out. Now they're back in. BRK completely got out of XOM and COP (goodbye oil) and increased their position in IBM(!) With good earnings and guidance Friday, it could be a beautiful week for DE. Welcome back, buddy.