First you need to define first what do you mean by stable coin? Because there are coins that are really stable means their value only rely on the price of fiat like USD. USDT or tether and TrueUSD are the examples of stable coins. They are not affected by the volatility of the cryptocurrencies. But if you are looking for coins that is not affected much by volatility, I think there is none. All cryptos except stable coins have unstable value, it can go high as much as it can or dip.