bloodroses :
How the heck did the stock holders not know this beforehand until Nvidia 'revealed' it?
HFT algorithms (and day traders) by definition don't care about long-term trends. They only focus on profit via the delta of buying low and selling high. So it's not like those that control the market don't know this. They know it. It's simply not in their interest to care. Now, for people like you and me that engage in the market at the human level, yeah, long-term matters.
Actually, if I recall, nVidia knows that this is a trap. It's why they didn't want to get involved in the crypto currency trend. On one hand, it's a major boost for the company. On the other, the whiplash from a correction later really takes the wind out from their sails.
I guess you could say that companies that engage in Cryptocurrency is a lot like doing coke. There's a major high at first, but the crash later leads to a long and lasting depression