Trading platform = shorting.
3 or 4 medium sized corporations with 3 or 4 multimillion shorts puts the prices in $10 or below in no time.
The ability to short doesn't magically allow the price to be driven down longer than the term of the loan contract. They have to rebuy the units they short-sold within the time limit, and if the rest of the market hasn't agreed with them during that period of time, they lose money on the short.
And further. All the ability to short on a market does is provide
stability to the market price, because shorters become buyers during a price dip (as they are taking profits). Stupid politicians think that shorting makes things crash faster, hence the regular bans during recessions.
Bitcoin must be the world's No.1 high-growth financial instrument, with a four-year track record which demolishes even gold's performance. Anyone/corporation attempting a long-term short would be totally insane. They would get more of a kick from sticking an electric eel up their trouser leg (it would be far cheaper!)