Way too speculative for new users. I think its the players themselves.
This might not be that known but Bitcoin has a stockmarcket with bonds and stock. For the volume of the coin, a significant part of the users of the coin are people trading and speculating with it.
They are way more comfortable and likely to play with a rise like this than any other.
Someone with 1000 BTC made over 60k dollars in a couple of weeks.
"Hey, internet money / commodities on the rise, buy now, sell for profit, I'm in!" times tens or hundreds of thousands.