**In America's Got Talent Season 21, the runner-up market reflects a wide-open field driven by the new Judges' Callbacks round and the absence of a clear frontrunner after auditions and Golden Buzzer selections.** Acts such as Unitree, Veronika Goroshkova, and Young & Strange sit near the top of trader consensus at implied probabilities around 44–50%, while a broad pack including ACRO Crew, Akira, Ashford Sanders, and Lai Noelle clusters lower, underscoring how the expanded live-show pipeline and celebrity guest judge input have leveled the playing field. Recent callbacks have rewarded acts that addressed judge feedback with polished, high-impact performances, yet no single contestant has posted the consistent audience or critic momentum seen in prior seasons. With quarterfinals still unfolding and voting volatility expected through the finals, traders are pricing in the unpredictability of live-show eliminations, viral moments, and last-minute standout routines that could shift the leaderboard before the finale.