(Undated) -- NBA free agency is up and running after a first day filled with signings and trades. The Bulls landed Lonzo Ball in a sign-and-trade deal, with the Heat doing the same to acquire Kyle Lowry. Chris Paul agreed to stay in Phoenix, signing a four-year deal worth 120-million dollars. The Lakers started their roster rebuild by signing four former players in the form of Trevor Ariza, Dwight Howard, Wayne Ellington and Kent Bazemore. Elsewhere, the defending champion Bucks brought back fan favorite Bobby Portis.