I don´t think there was a airdrop of waves. I think it was a Initial Coin Offering / ICO at the beginning of this coin. And they rised a ver huge amount of money there. And at this time the bitcoin price was very low.
Waves is big project that's why can raised very huge amount of money and now time bitcoin price very high and waves coin price is down, i hope waves coin price can recover above $5 after bitcoin hardfork finished