TBM7 pilot reported experiencing a loud bang and jolt in flight with no apparent cause. Post flight inspection did not reveal any abnormalities.

Narrative

Momentary event causing a loud 'bang' and violent jolt of the aircraft. Uncertain whether cause was Clear Air Turbulence (CAT); wake; or collision with object. Interim aircraft inspection reveals no indication of collision. Aircraft otherwise operated nominally.Departed the ZZZ [area] in light winds; no turbulence or nearby clouds. Flight was nominal. We suddenly felt a severe jolt and loud 'bang'; passenger hit head on ceiling notwithstanding wearing a restraint; but no injury. Autopilot decoupled followed by slight altitude excursion and then immediate recovery. We first believed something hit the underbelly of aircraft. We identified nothing visually from the cockpit. Engine/instruments and control surfaces functioned nominally. No weird smell or any indication of bird or other FOD collision or ingestion. We had little baggage; two souls on board; about 2/3rds fuel.I made a precautionary landing in ZZZ1 given its long runway and available services) and then continued to planned destination of ZZZ2 without incident. Gear extension during approach to ZZZ1; subsequent gear retraction followed by gear extension for ZZZ2 were nominal. Post-flight inspection by me showed no observable damage; ingestion of FOD; bird strike; feathers; blood; or drone strike. Aircraft structures inspected appeared nominal. I've scheduled an Inspector to validate.Requested ZZZ Tracon to pull the radar data to determine if wake turbulence could have been a factor; yet no nearby aircraft identified other than two CRJs 3000 and 4000 ft. above; respectively -- and their positions unlikely to have created wake in my flight path. I've previously experienced severe turbulence; both CAT and wake; and the immediate situation seemed very different. I also contacted Weather Services of record of any relevant possible weather phenomenon; awaiting their response. So; cause remains a mystery.