feather one's nest

verb1

1. •
   To achieve benefits, especially financial ones, by taking advantage of the opportunities with which one is presented; to amass a comfortable amount of personal wealth; especially, to do so to a degree that involves venality (e.g., insider trading, police corruption).

   • It may do him some harm, perhaps, but Dempster must have feathered his nest pretty well; he can afford to lose a little business. — 1857