They actually did VERY well off of Trump's military budget expansion. The problem is, unless the military goes out and gets shit destroyed in war, there s not much money to be made replacing destroyed humvees, tanks, planes, etc. You, as a seller, want that stuff to be considered consumables, but if your customer isn't warring and getting shit destroyed, that's hard to do.

Companies like Halliburton and Dyncorp, who make money supporting war efforts by building bases, operating mess halls, etc. don't get a lot of contracts in peace time, so war is good for their bottom line. Trump leaving Syria, and drawing down in Afghanistan and Iraq was probably not that good for those kind of companies.