You are wrong. BTG price dropped 97% from its INITIAL VALUE. Pls go check some other coins: their initial value and current.
What does "INITIAL VALUE" mean? Zcash at it's start was about 1000 BTC per ZEC. And so what? Is it initial price? It should observe any coin at least several month to get it's more or less adequate market price
Indeed they didn't sell this coin it is fork on the original blockchain so market value depend on the market. This is airdrop coin for all BTC holders and at this point most of them sold this without any mercy. Now it is moving as per mining cost and there are some updates in future will make this interesting.