Earlier quoted context omitted.
That is not an irrational consideration: a dump of such a large amount would definitely drop the price of bitcoin. So if the bidder for the coins can get a 20% discount on 16 million dollars, and then drop them of on the market gradually, he might make a 5% of the initial investment. If eh discount is larger, so would the profits. What the market is doing definitely affects the decision to do a bulk purchase and dump…
It does seem an irrational consideration - why is 30k BTC (less than $20m) labeled "such a large amount" instead of "irrelevantly small amount" ? Even for BTC scale, this amount shouldn't be a big deal by itself. $20m or 30k BTC simply is not big in the financial market sense - it's a big amount for an individual or a single small company; but that's not a significant amount at all for supply/demand of any currency w…
Even for such a small coin, $5k was well below the typical daily trade volume. But here's the thing: He very rapidly bought off pretty much all the sell orders at 4 satoshi, and everyone started speculating what happened and prices shot through the roof, even though more coin than that enters the supply in no-time through mining still.
Point being that coins worth a typical daily trade volume can be enough to trigger large reactions in markets that are priced so extensively based on speculation about how other speculators will behave (take a look at the chat at various exchanges, and see the amount of chatter about which coin to buy into because they expect a pump or other forms of manipulation - very little of the chat seems to be related to non-speculative uses of the currencies).