The notable increase in the Polymarket prediction market from $0.19 to $0.43 for President Joe Biden officially withdrawing from the 2024 US presidential race likely reflects several key developments, including impressions from the recent presidential debate. Held the night before on June 27, 2024, the debate featured intense scrutiny of Biden's performance and policies, with commentators noting moments where Biden appeared less energetic or assertive compared to his opponents. These observations further fueled speculation about Biden's ability to sustain a competitive campaign, especially as concerns about his health and stamina had already been circulating in the media.