My guess will be like this
someone rich
decided to invest into onion coin
well, if you think = it is wise, because the supply is thin, the coins circulates in a few number on the market and it is hard to mine, so miners will not harm too much dumping daily volume and I think this investor can't take a part in airdrop
so what choice does he has? just buy from exchange, but taking to the account that supply is limited, he bought all coins with a cheap price, then continue and continue to buy coins with higher and higher price.
that is all