I have no idea whether they do or they don't. I have no problem with working on the assumption right now that you're correct in your claim. However, that's not the fault of bitcoin. Those are the actions of the irresponsible.I claim then that enough people behave without common sense - by buying bitcoins in order to sell them later with a profit and by holding significant amounts in online wallets.
Its like the analogy I provided....you wouldn't walk down the street with 100k in your pocket.
If you mean they're shorting, then that may be true - but that's not my world. That said, if we are talking about selling bitcoin - you can have bitcoin in cold storage and move it rapidly - be that to an exchange or elsewhere.
Buying is more precarious - ironically due to the fact that it takes so long by conventional means to move FIAT into your trading account.