Is there any reason why the btc price is dropping that much today? Are people scared by the hard fork or why is it dropping?
Probably that is the main reason. As far as I remember, in the recent segwit2x last August, same thing happened, its market valu dumped before the fork and increase right after it. And maybe that's the reason why the value of Bitcoin is stucked at 6000$ and will also probably increase after the fork and make it possible to reach 7000$ before this year end.
The way that price dumped (and alt prices rose) immediately after the BTG snapshot suggests that some people were holding BTC to get BTG. After the snapshot, they were free to dump again. Doesn't really make sense because it's just a scamcoin, but there was a lot of hype around it. I don't even understand how it's trading on Bitfinex, since the blockchain isn't even public yet. The blockchain might not even exist yet...