The trader consensus favoring no calendar Grand Slam in 2026 reflects the extreme difficulty of claiming all four majors—the Australian Open, French Open, Wimbledon, and US Open—in one season amid shifting surfaces, travel demands, and intense competition. Historical records confirm this achievement has not occurred in the Open Era for men since the late 1960s, with physical tolls, injury risks, and deep fields routinely disrupting even dominant players. Carlos Alcaraz carries the lone visible implied probability thanks to his proven versatility across hard courts, clay, and grass plus recent form, yet barriers like potential setbacks, rest management, and rivals such as Jannik Sinner could still intervene. Any realistic path would require flawless execution without late scratches or form dips through the full schedule.