Powerhouses at the Ninth Form of the Saint Celestial Stage from a force would usually leave their belongings to their forces before they faced the Heavenly Tribulation. However, there were quite a few sectless cultivators who were at the Ninth Form of the Saint Celestial Stage. They did not belong to any force, and most of them did not have family or friends.
Before these sectless cultivators pass the Heavenly Tribulation and ascend, or die in an attempt to ascend, they would mostly hide their Spatial Rings that contained treasures somewhere. These places were later known as treasure vaults.
The possessions of powerhouses at the Ninth Form of the Saint Celestial Stage were undoubtedly treasures!