It is just like FIAT. Money around the world is around 1 Quadrillion and how much are being traded in Stock Market worldwide about $90 Trillion.
Most likely Bitcoin that is not being traded is just stored in their wallet.
well, if this is true, that means the bitcoin can be manipulated by those who store it in large numbers and we cannot know who they are. Let's say satoshi nakamoto, he could be truly have a 1 million BTC and its not impossible at any time they sell all the bitcoin they have and 'booom', bitcoin prices will be back in the $1000 lift or worse than that.
I would have to agree on the above statements where bitcoin in large scale were perhaps being kept by the big investors waiting for the biggest pump to happen. And when that time comes, definitely stored bitcoin will be out on the cage where it was kept for good. Circulating btc's could not be the actual btc's that are circulating in the market because of the large btc safe keeping. This is just my opinion.