If you regulate the Bitcoin with proper regulations like we see in the Japan nothing will affect the BTC price or any cryptocurrency but cheapest country like US and all will not allow BTC boom.
So they will put the struggles for sure. So soon if we boycott those countries we can see BTC go bigger.
It affect the market too much, it maybe to make it higher or lower. Some needs regulation to think that they put their money in a safest way as it will be acceptable in the government and have concern on it. And may decrease the price as the existing or old investors, see no difference in using it other than the normal mobile banking. Hopefully, it will be favorable to both new and old crypto investors.