Always try and find the most likely logical solution, but it is also entirely possible for it to be the most unlikely cause - and still not be paranormal.
In this case it is possible for it to become temporarily lost, only to be found by a so-called friend later who then steals it - thinking it won't be missed if it was already out of sight. This would be typical if it was down the side or back of a chair, they might help themselves to loose change in sofas all the time.
It is still possible to be paranormal, but as nothing else is going on I would doubt it. No weird popping noises, glasses shattering, items being thrown, liquids running down walls, fogs, smells or getting shoved or pushed by spirits - I think we can choose the logical option instead.