Semifinal first-leg results have traders pricing Bayern Munich, PSG, and Arsenal within 3% implied probabilities, reflecting razor-thin aggregate edges ahead of decisive second legs on May 5. PSG's thrilling 5-4 home victory over Bayern in a nine-goal classic showcased attacking firepower from both but exposed defensive frailties, with PSG now facing Bayern's Allianz Arena without key right-back Achraf Hakimi due to injury. Meanwhile, Arsenal's gritty 1-1 draw at Atlético Madrid—marred by a controversial penalty overturn—leaves the tie wide open for Emirates return, where Gunners' home form could tip scales. Atlético trails at 8.9% amid Simeone's pragmatic style, while quarterfinal triumphs (Bayern over Real Madrid 6-4 agg., PSG over Liverpool 4-0, Arsenal over Sporting 1-0, Atlético over Barcelona 3-2) underscore the quartet's knockout pedigree.