But he is lying. How can he have that many bitcoin? I'm just worried people believe it and the price stays down. I have bought bitcoin because it is digital gold so I don't want the price going down.
If you think that he is lying about the amount of coins he holds then why worrying about it, people who invest money in bitcoin does not get fooled by speculation and hence the price cannot be dragged down because someone said so in twitter that they will be selling their coins. If there is a legit reason to worry then people might stay away until all the coins are dumped in the market and then people will start investing in them.
Do you think Craig really is Satoshi then?

Otherwise how could he have those bitcoins to sell?

You really could mine millions of coins if you started mining during the initial stages and you really do not necessarily be Satoshi to have those kind of coins

.