Justin Gaethje holds the undisputed UFC lightweight title after stopping Ilia Topuria in June 2026, and with no title defense scheduled before year-end, traders see him as the overwhelming favorite to remain champion at the close of 2026. At 37, Gaethje has cited injuries and family considerations while confirming he will not compete again this year, leaving the division in limbo as contenders like Arman Tsarukyan build momentum with recent wins. The wisdom of crowds reflected in current pricing accounts for the short remaining timeframe and absence of imminent title bouts, though scenarios such as an unexpected retirement announcement leading to a vacancy or a rapid interim-title resolution could still alter the outcome before December 31.