This dumper is clever, he knows BTC is worthless and USD talks. Who in their right mind would sell 500 BTC batches for 450 when their value is at least 10 billion dollars, right?
BTC is worth as much as people are willing to pay for it. Hypothetical values mean nothing. Besides, if you hold several batches of 500 BTC there are much better investments that can be made rather then holding bitcoins for several years hoping it will burst in price. Time is money and currently, BTC is a waste of time.