I am absolutely sure Satoshi owns a very big amount of bitcoin because in the pre sale of bitcoin a fixed number of bitcoins was pre-mined and I dont think all of them were sold wich leads to the point that the remaining amount of bitcoins are in the possession of Satoshi. Also, being the creator of Bitcoin, Satoshi knows all the secrets of it and I am sure he can somehow hack the system.
Bitcoin didn't have a "pre sale".
The Bitcoin protocol was published before the first bitcoin was generated, and the Bitcoin software was made public at around the same time the genesis block was generated.
Bitcoin was not pre-mined. It simply started with the genesis block and various people mined subsequent blocks. It wasn't until a year or so later when bitcoins were sold for fiat money.
There are no Bitcoin secrets. The software and protocol was always public, and it has been analyzed to pieces. At this point Satoshi doesn't know anything more about Bitcoin than anyone else, except for its early history and the identity of its creator.