Coinmarketcap said altcoins like Polkadot and Cardano saw huge gains on Monday, after a relatively calm holiday weekend. Both coins rose more than 6%.

Meanwhile, the largest cryptocurrency, Bitcoin, rose only 2.5% to $ 51,575. Ether also rose by 0.4% and traded around $ 4,100.

Miller Tabak chief market strategist Matt Maley said: "there is no question that Bitcoin's dominance has waned recently."

This is not the first time that altcoins gained traction as many performed impressively this year. Dogecoin, Cardano and Shiba Inu, formerly relegated to the most speculative corners of the market, have become household names this year and have set their all-time highs.

"Bitcoin is making rapid progress within the global economy but it's easy to see how that headway is being outpaced by some of the smaller and faster-growing networks," said Mati Greenspan, founder and CEO of Quantum Economics.

This dynamic reduced Bitcoin's dominance and, according to a CryptoCompare report, total assets under management of Bitcoin-related products fell 20% to $ 39 billion in December. The decline lowered the share of Bitcoin products in the crypto market to 67.8%, from 70.6%.

According to Coinmarketcap, Polkadot and Cardano have gained over 25% in the last seven sessions.

Bitcoin, on the other hand, underwent strong volatility in November, with it dipping by 10%, on pace for its second consecutive monthly decline.

Maley said investors shouldn't go too far on the scale of risk when it comes to cryptocurrencies. "Like it was with the internet stocks in 2000, only the best survived in the long run," he said.