All of the pre-sale participants were BTC holders because that is the only currency the Foundation accepted for presale Eth.
The question is how many of those BTC holders there are and whether presales/ICOs usually follow that pattern. Most don't, they use all their powder in the beginning (there's no Indian summer surge of donations towards the end of the sale). Even when they do it is not as pronounced as here. That's what makes the curve weird.
The question is how many of those BTC holders there are and whether presales/ICOs usually follow that pattern. Most don't, they use all their powder in the beginning (there's no Indian summer surge of donations towards the end of the sale). Even when they do it is not as pronounced as here. That's what makes the curve weird.