what is a good way when cryptopia adds a coin, or binance or bittrex.
If you are looking for exchanges that will list a new cryptocurrency you want to invest/trade, the best way is always visit their website, official blogs, or their social media account. Exchanges usually make an announcement whenever they will support a new cryptocurrency and add it to their service but I think not always so another way is to check the channels that developers of that coin usually use (like telegram, reddit, slack, twitter). They will surely announce on which exchanges their cryptocurrency will be listed or when.
