There's simply no stopping cryptocurrency valuations of late. During the morning hours of Jan. 7, the combined value of all digital currencies nearly touched $824 billion. Mind you, on Dec. 31, 2016, just 53 weeks earlier, they sat at a mere $17.7 billion. We're talking about a more than 4,500% increase in value in just a shade over a year's time.

Bitcoin, the world's largest cryptocurrency by market cap at $285 billion, usually gets a lot of credit for being the impetus behind this rally. After all, bitcoin is responsible for almost 35% of the aggregate cryptocurrency market cap and is the world's most popular virtual coin among investors and merchants. It also helped to bring blockchain technology -- the underlying digital and decentralized ledger that records all transactions -- into the mainstream.

But for as great as bitcoin has been, the past couple of months have really been about everything but bitcoin. Cryptocurrency investors are on the hunt for the next bitcoin, and it's generated some incredible gains in the virtual currencies creeping up in bitcoin's rearview mirror.

Last year's cryptocurrency darling could take a back seat in 2018

Perhaps no digital currency has emerged from the shadows more prominently in recent weeks than Ripple and its coin, XRP. Over a trailing one-month period through Jan. 7, Ripple has risen by more than 1,300% to a market cap of $121 billion, and since the beginning of 2017, XRP has skyrocketed by 48,744%, according to CoinMarketCap.com! Not too shabby.

Ripple has relied on a handful of catalysts to push its coin higher. This includes multiple blockchain partnerships with global banks, now-foiled rumors that Ripple would be added to Coinbase soon (Coinbase is the world's most popular cryptocurrency exchange), and a cohesiveness between its virtual coin and blockchain that many of its competitors simply don't have.

Of course, a repeat its performance in 2018 could prove difficult for Ripple. Following a nearly 50,000% romp higher, investors will likely look for tangible results and new partnerships before they consider buying into the Ripple story. This could open the door for lesser-known cryptocurrencies to run circles around this recent darling in 2018.

While there are absolutely no certainties in the cryptocurrency realm, and it'd be hard to argue against these virtual coins not being in a valuation bubble at this point, the following three cryptocurrencies could leave Ripple in their dust this year.

Stellar

Though Stellar has already had an incredible start to the new year, it might just be clearing its throat for an even more substantive run higher.

The story behind Stellar, like Ripple and practically every other cryptocurrency, is all about its blockchain technology. Whereas Ripple is laser-focused on big banks and financial institutions, Stellar is more oriented to going after big multinational businesses, and snagging financial institutions as a secondary source of inspiration. To date, it's landed one elephant: IBM (NYSE:IBM).

This past October, Stellar announced that it was partnering with IBM and KlickEx, a payment processor, to test its blockchain in real-world cross-border transactions in the South Pacific region. The partnership entails a dozen large banks in the South Pacific developing and deploying Stellar's blockchain technology in order to process payments from IBM's customers to the company. This should allow Stellar to show off its roughly two-to-five second processing time, which is light-years quicker than bitcoin's blockchain processing time, as well as its ability to handle multiple different currencies. Most importantly, if this real-world test works out, Stellar will an opportunity to scale its technology, assuming IBM expands the project.

If Stellar can stay in the headlines by adding a new partner or two, or if it can get great feedback from its partnerships with IBM and/or KlickEx, it could very well outperform Ripple.

IOTA

Another stealthy cryptocurrency that could rise from the shadows and potentially run circles around Ripple in 2018 is IOTA, which is overseen by the IOTA Foundation, a German nonprofit.

Stop me if you've heard this one before: It's all about IOTA's blockchain technology! However, IOTA's blockchain comes with in intriguing twist. In late November, the IOTA Foundation announced the release of its "Data Marketplace," which is a "blockless" blockchain that serves as a marketplace where businesses can sell and share data that would otherwise be wasted.

What's "blockless," you ask? Unlike most blockchain networks that are open source and charge transaction fees on their networks, IOTA's blockchain is open source and free for users on the network. Thus, IOTA may have resolved three major issues at once with its Data Marketplace: the removal of transaction fees, the ability to scale its technology, and a reduction in wasted data.

Though IOTA has yet to secure any formal partners as of mid-December, it does have over 35 companies as active participants in its open innovation initiative. Some these companies include Accenture, Fujitsu, and telecom providers T-Mobile and Orange, to name a few. This doesn't in any way suggest that IOTA will land genuine partnerships in the future, but having such brand names involved as demo participants is a major step forward for such a unique idea.

Komodo

If we dip even further into lesser-known cryptocurrencies with a chance to run circles around Ripple, we would come to Komodo, a virtual coin (KMD) with a $1 billion market cap at the moment. Like the other digital currencies discussed, the story here is all about blockchain -- and it's differentiation from the pack.

Komodo is part of a newer movement in cryptocurrencies that some would call an evolution from the likes of bitcoin -- privacy coins. Privacy coins take the perceived anonymity and privacy of cryptocurrency transactions, which isn't always there, and cranks it up a whole bunch in order to obfuscate the identity of a sender and receiver of funds, as well as the transaction amount.

If that's not interesting enough, here are two other tidbits that merit Komodo being on the radar for cryptocurrency investors. First, Komodo describes itself as a gateway to 32 other stable Komodo currencies. In effect, it plans to launch 32, independent, fiat-pegged cryptocurrencies that'll, in theory, allow for seamless conversions between fiat and digital currencies.

The other really unique aspect of Komodo is that it's put its own tweak on bitcoin's proof-of-work validation protocols that it refers to as delayed proof-of-work (dPoW). With dPoW, protocols notarize the blocks on the blockchain, ensuring immutability (i.e., the inability for data or blocks to be altered), and adding yet another layer of security. In essence, to change Komodo transaction data, a cybercriminal would first need to alter bitcoin's blockchain, which isn't possible.

It may be out of sight for many cryptocurrency investors, but Komodo could leave Ripple eating its dust.