what you mean "overtake"? if you are talking about the market cap, soon altcoin will be a new king 
EOS and Ethereum have a big potential to replace bitcoin
However, I think altcoin price can't exceed the bitcoin price!
no one can overtake Bitcoin, even though there are some Altcoin that have good potential and many believe it. so far the value of Bitcoin always occupies the top position and no one can match it. in my opinion it is difficult to overtake Bitcoin and whenever Bitcoin becomes king of coins, it is possible that in the future do not know when there will be increasingly sophisticated technological tools so that their abilities are greater.EOS and Ethereum have a big potential to replace bitcoin
However, I think altcoin price can't exceed the bitcoin price!