Ripple, or XRP, would only need to get to $6.57 for its market capitalization to be bigger than bitcoin's.

Price of ripple plunged on Monday.

Ethereum would only need to rise 132 percent from its current price to surpass bitcoin.

Crypto class: How to buy ripple

Market capitalization has become an obsession with many cryptocurrency watchers.

It refers to the value of the entire digital currency in circulation and is worked out by multiplying the supply of the virtual coin by the price per unit.

With bitcoin, the largest cyrptocurrency by market cap, having a quiet start to the year, many investors are looking at alternative cryptocoins. Ethereum and ripple, for example, have seen fairly strong rallies to begin the year. And many are wondering which one could usurp bitcoin as the biggest cryptocurrency.

Ethereum and ripple have been jostling for the second spot, and that has changed depending on price.

That jostling turned volatile on Monday as the price of ripple tumbled. Bitcoin also fell, while ethereum gained in value.

Ripple's current circulation is 38,739,144,847 digital coins. At Monday's earlier price of $2.49, its market cap was $96.46 billion, according to CoinMarketCap.com. Bitcoin's market cap, meanwhile, was $254.2 billion on Monday.

For ripple to surpass this, the cryptocurrency would only need to get to $6.57. This would require a rise of 164 percent. It rose nearly 36,000 percent last year.

Ethereum has a circulating supply of 96,846,982. Its current price is $1,119, according to CoinMarketCap. Its market cap is $108.3 billion. Ether would need to rise to around $2,700 to surpass bitcoin's value. This would require a 134 percent rally from Monday morning's price, which is smaller than the rise required by ripple.

Both these cryptocurrencies benefit from having larger circulating supplies than bitcoin. It means the price of each digital coin can be lower to achieve a higher market cap. Bitcoin's supply is capped at 21 million with the current supply standing at 16,789,425.

With bitcoin's dominance standing at record lows, and alternative cryptocurrencies seeing big price leaps, it's not inconceivable that either ether or ripple could claim the top spot in terms of market cap soon.

Of course, if bitcoin sees a surge in price this year, it will make it harder for either cryptocurrency to surpass it.

Still, some experts have suggested that ripple has run ahead of itself. Ripple works with large institutions and unlike bitcoin, many of the coins are actually owned by the company. This means it's not as decentralized as bitcoin is.