The Pirates have signed Brooks Pounders, who was their second-round pick and their third pick in the draft (an earlier second-round pick, Victor Black, was a compensation pick for the Bucs not signing Tanner Scheppers last year). Pounders is a high school pitcher from the San Diego area. He was a USC recruit. He'll start off at Bradenton. I'm not yet sure how big his bonus was.
My guess--and it's only a guess--is that we'll see a few other top picks (perhaps Black and third-rounder Evan Chambers) sign fairly quickly before the bigger dominoes (Trent Stevenson, Colton Cain, and hopefully Zach Von Rosenberg) start falling.