Buying altcoins does not make you to loose, it depends on the type of altcoin you are buying. It is even possible for you to buy from the top 10 and still loose. You just need to do your research before buying any of them, whether top 10 or from to 100.
I agree with you, because the top 10 is a coin that has a large volume, so to get a profit, it has a greater chance compared to the coin tangb has a small volume