There are many good exchanges in this market, so it all depends on the altcoin you want to buy. And if you want to have the highest security, you should choose Binance, they are the best and safest exchange for everyone to use.
I agree with you. There are a lot of good exchanges available for investors right now but I would advise you to choose only exchanges like Okex, Huobi, Binance as these are the 3 biggest exchanges in the crypto market. Of course, there will also be a lot of good investment options here as any of the projects listed here are very carefully examined so there will be a lot of risk reduction in investing.