That's true, but you don't need to mine if you want to speculate and you don't need to speculate if you want to mine. They're really two independent processes.
I would also be willing to bet that a "speculator" is expecting Bitcoin to go above $290. If they thought it was capped at $290, there wouldn't be much point in speculating, would there?
Well, short sellers will. They have dominated the market for the past year, and will continue to sell other peoples' coins on margin all the way to the bottom if they can. Many do not care about Bitcoin much as a tech, but want to make money. Lots of them are not even particularly skilled traders. Shorts are at an all time high and will probably get squeezed big time in the coming months. It will have a spring like effect.