I heard the information TRON and EOS coming out the mainnet, then the CMT ran the testnet. What is the mainnet? and testnet? Why are coin prices increasing when mainnet is launched?

When buying crypcurrency, Buffett said, "You do not invest when you do it. You are speculating. There is nothing wrong with that. If you want to bet others will come and pay more money in the near future, it's a kind of game. But that is not investment. " Are we participating in a game?

I want to buy less Helbiz coin but I do not know where to buy the price? Who can help me. Thank you!