btc or altcoin all carry the same risks. differences in price occur because of differences in coin supply and interest demand. altcoin features are even more complete than btc. but never mind, because BTC is not bad. so choose coins according to your needs and abilities.
If it's investement, i'll preffer bitcoin. not say that altcoin are bad, but need more comperhensive research to invest on altcoins. it's also will depends on your strategy how you invest and how you make a profit