Ethereum ETH, Monero XMR, FCT Factor, DASH, are the top coins and have the most trading volume each day.
The Altcoin is all trying to overcome the weaknesses of Bitcoin.
Litecoin, for example, has improved the time to update each block, leading to faster time to transaction confirmation. Monero to Enhance Security in Transactions
However, no Altcoin is perfect, maybe it will be strong at this point but there will be some point deduction. It is also a factor that helps to boost the e-money ecosystem to grow stronger to meet the different needs of users.
With the new Altcoin appearing, the value of the change is multiplied rapidly. Initially, when they hit the market they have a low price (the total value of the currency). Rich traders (whales) often inject large amounts of capital into low-priced currencies to build up hype and increase prices.

But bitcoin still holds the upper hand in the market despite the fact that the altcoin is gradually strengthening.