A new Polymarket code is active for Sunday evening’s MLB slate, with the Red Sox game already underway and Zack Wheeler set to take the mound for the nightcap in Philadelphia. The Polymarket code MASS is a verified registration code that unlocks a $50 trading bonus for new users who deposit $20 at sign-up — bringing their total starting balance to $70 across Polymarket’s full catalog of live prediction markets, including tonight’s games and the …