As 2018 is getting under way, there has already been some exciting price movement among leading cryptocurrencies.

After falling to the $13,000 range earlier Tuesday, bitcoin shot back above $15,000 on reports that Peter Thiel, a venture capitalist and early Facebook investor, is betting millions of dollars on the digital currency. In addition, over the past week, Ripple has overtaken both bitcoin cash and Ethereum to become the second-largest cryptocurrency, and Cardano is the latest newcomer to the top five.

A gold token with the bitcoin symbol on it in someone's palm.

Image source: Getty Images.

Today's cryptocurrency prices

Here's a look at the six largest cryptocurrencies by market capitalization, and how much each has changed over the past 24 hours, as well as since last Friday before the long holiday weekend.

Cryptocurrency Name (Code)

Price in U.S. Dollars

Day's Change

Since Friday 12/29

Bitcoin (BTC)

$15,150

13.5%

2.8%

Ripple (XRP)

$2.09

1.9%

28.2%

Ethereum (ETH)

$845.77

13.5%

12.5%

Bitcoin Cash (BCH)

$2,596.80

11.5%

(5.1%)

Cardano (ADA)

$0.76

7.2%

90.3%

Litecoin (LTC)

$253.81

12.7%

0.7%

Data Source: investing.com. Prices and daily changes as of Jan. 2, 2018 at 3:10 p.m. EST, and prices are rounded to the nearest cent.

After initially trading in the red for the day, bitcoin got a major boost on reports that Thiel's Founders Fund has invested $15 million to $20 million in the leading digital currency, and the fund's holdings are now worth hundreds of millions.

Ripple soared over the holiday weekend

After rising by more than 75% last week, Ripple climbed by another 28% over New Years' weekend to overtake Ethereum as the second-largest cryptocurrency by market cap. In fact, with a market cap of $94.4 billion, Ripple's total market value is about 40% of bitcoin's.

The simple version of why Ripple is surging is because it continues to emerge as the cryptocurrency with real, practical applications that could conceivably be used on a mainstream basis. The currency is being used in a partnership with American Express, which has said that XRP (the official name for Ripple's currency) will be used to hasten Amex's payment speeds "later on." Ripple is also being used to link to Santandar for instant U.S. to U.K. payments.

There are several rumors swirling about Ripple, such as additional banking partnerships and availability on Coinbase and other major exchanges. If these turn out to be true, Ripple's gains could certainly continue.

Cardano surges to overtake Litecoin

The other major shake-up in the cryptocurrency landscape this weekend was the surge of Cardano, which has risen to a total market value of more than $20.5 billion. This is even more impressive considering the currency only exceeded $1 billion in market value about a month ago.

Without getting too technical, Cardano aims to solve several problems and challenges that other cryptocurrencies face. For example, Cardano's blockchain is reportedly the first to use a "provably secure, proof of stake algorithm," according to BanklessTimes.com. It also has scalability (one of bitcoin's biggest challenges is that its network can handle relatively little transaction volume) and can handle transactions more rapidly.

Still a volatile market

If the cryptocurrency activity during the past weekend is any indicator, this not only remains a highly volatile market, but the volatility among leading cryptocurrencies other than bitcoin actually seems to be accelerating. The cryptocurrency market is still very much in its "wild west" stage, so if you plan to speculate, it's important to only do so with money that you can afford to lose.

Matthew Frankel owns shares of American Express. The Motley Fool recommends American Express. The Motley Fool has a disclosure policy.