Bitcoin should not be compared with owning stock in companies. There are plenty of companies that have failed spectacularly throughout the time, big ones like Nokia, Blackberry, AOL, Myspace etc. That guy had plenty of reasons to sell

Bitcoin is a protocol, like the BitTorrent protocol, like the Hypertext Transfer Protocol. IT CANNOT FUCKING FAIL!

Bitcoin's success is one of the most predictable outcomes in the history of our lives. Most of us know that BTC will inevitably go into trillions in market cap, yet you can still find greedy imbeciles that are willing to participate in these stampedes to the bottom. The only thing that I'm uncertain of is whether these dumps are being started by the imbeciles that I was talking about above or by Tether and Bittfinex, two entities that for some reason, nobody can stop.