There are 1,662 cryptocurrencies in existence as of this writing, according to investing.com, but only a few dozen are what I would call "significant players." Not all cryptocurrencies are unique and useful enough to become serious contenders to disrupt our financial system -- I'm pretty sure my local retailers aren't going to accept Mooncoin or DeepOnion anytime soon (and they're in the largest 20% of cryptocurrencies). However, there are certainly some that could potentially become household names in the future -- and not just bitcoin, either.

With that in mind, here's a list of the 15 largest cryptocurrencies by market cap right now and a quick, simple English description of how each one could become a major disruptor in the global financial system.

Stacks of gold coins etched with the bitcoin symbol.

Image source: Getty Images.

Cryptocurrency Name (Code)

Price in U.S. Dollars

Market Capitalization

Bitcoin (BTC)

$8,352.50

$141.43 billion

Ethereum (ETH)

$536.60

$52.65 billion

Ripple (XRP)

$0.67

$26.70 billion

Bitcoin Cash (BCH)

$969.32

$16.38 billion

Litecoin (LTC)

$156.06

$8.72 billion

Cardano (ADA)

$0.17

$4.57 billion

NEO (NEO)

$61.60

$4.32 billion

Stellar (XLM)

$0.23

$4.26 billion

EOS (EOS)

$5.32

$3.96 billion

IOTA (MIOTA)

$1.29

$3.61 billion

Monero (XMR)

$212.00

$3.34 billion

Dash (DASH)

$392.70

$3.12 billion

NEM (NEM)

$0.28

$2.56 billion

Tether (USDT)

$1.00

$2.21 billion

Tron (TRX)

$0.03

$2.01 billion

Data source: www.investing.com. Prices and market capitalization as of March 6, 2018, and prices are rounded to the nearest cent where appropriate.

What's the difference -- don't these all do the same thing?

You may be asking, "Why do we need so many cryptocurrencies and how could they all possibly be useful?" The short answer is that while bitcoin was a revolutionary first step, it is far from a perfect cryptocurrency. To name a few challenges, transactions can take a long time, fees can be relatively high, and the network isn't as scalable as it needs to be (yet). So, most of the other major cryptocurrencies improve on some of these.

Here's a quick description of each one -- and some links if you're curious to learn more.

1. Bitcoin

Bitcoin was the original cryptocurrency, and is the original form of blockchain technology. And like the first version of any technology, there are some shortcomings. However, bitcoin is still the most valuable cryptocurrency by a wide margin, and several companies are working on solutions to make the bitcoin network faster and more scalable.

2. Ethereum

Unlike bitcoin, however, Ethereum isn't designed to be a payment currency. Rather, Ethereum's digital ledger uses protocols known as "smart contracts," designed to be attractive to businesses. In short, Ethereum's smart contracts verify and/or facilitate a contract -- for example, an Ethereum smart contract can allow money to be spent only when a combination of people agree. More than 200 organizations are currently experimenting with Ethereum's technology, such as JPMorgan Chase, Mastercard, and Cisco Systems, just to name a few.

3. Ripple

Ripple is developing its technology specifically for the banking industry to facilitate cheap and efficient cross-border payment transactions. Its near-instantaneous settlement times and next-to-nothing transaction fees are clearly attractive, as the company has already scored partnerships with American Express, Santander, and MoneyGram International, just to name a few.

4. Bitcoin Cash

Bitcoin Cash was spun off from bitcoin in 2017, in a process known as a "hard fork." The basic idea behind Bitcoin Cash is that the size of each block is larger, therefore more information can be processed in a given time period, and the result is fewer delays and lower transaction costs than bitcoin. The goal was to make Bitcoin Cash a more useful currency, rather than just a long-term store of value.

5. Litecoin

Litecoin is commonly referred to as the silver to bitcoin's gold, and like Bitcoin Cash, also came from a hard fork in bitcoin, although it happened a while ago (2011). Litecoin has implemented the SegWit protocol, which essentially gives it better transaction times and fees than bitcoin, and has a different mining mechanism and processes blocks at four times the rate of bitcoin's network.

6. Cardano

Cardano is a third-generation version of blockchain technology. It aims to improve upon the shortcomings of first-generation (like bitcoin) and second-generation (like Ethereum) predecessors. You can read an excellent technical overview by my colleague Sean Williams, but the idea is that Cardano will use a multilayered smart contract system (Ethereum's smart contracts are single-layered) and will be much more secure, which could appeal to customers like financial institutions.

7. NEO

NEO is another cryptocurrency that focuses on smart contracts, like Ethereum and Cardano. Unlike Ethereum, NEO was created primarily for use in the Chinese market, and is often referred to as the "Ethereum of China."

8. Stellar

Like Ripple and Ethereum, Stellar's blockchain technology is designed to attract enterprise customers, offering processing times of just a few seconds. Stellar isn't just focused on banks -- the company has a partnership with IBM to process international transactions that will process almost instantly.

9. EOS

One of the newer cryptocurrencies on the list, EOS plans to be the best protocol for decentralized applications. In plain English, EOS's goal is to be a better version of Ethereum. EOS aims to be able to process up to 50,000 transactions per second -- by comparison, bitcoin can process three to five transactions per second, and Ethereum can handle about 15. Even Visa's payment processing network handles less than half of what EOS plans to do.

10. IOTA

IOTA is run by a German nonprofit, and aims to be a revolutionary form of blockchain technology (I know, this is starting to sound familiar). The big advantage of IOTA is that its blockchain is free for users, meaning that there are no transaction fees. IOTA also has a high network capacity, so it's not too surprising that it's getting some interest, as transaction fees are often a major complaint among cryptocurrency users.

11. Monero

Like bitcoin, Monero is designed to be a currency. However, whereas bitcoin seems to be getting less and less private as time goes on, Monero is a "privacy coin." That is, it's designed to emphasize the anonymity of the people using the currency with a protocol called CryptoNote, which makes tracing payments extremely difficult.

12. Dash

It seems like the big trend for new cryptocurrencies is to focus on enterprise clients and processing "smart contracts," rather than be a good currency. However, Dash is all about improving on bitcoin to create a practical, spendable currency (digital cash) for everyday transactions. Dash offers instant transactions, private transactions, and a self-governing and self-funding network. It also aims to be more consumer-friendly, with all merchants that integrate the digital currency searchable on the blockchain, so the question of "where can I spend my cryptocurrency?" could become a thing of the past.

13. NEM

NEM aims to be a "smart asset system," and is meant to solve the problem of integrating blockchain technology into existing payment networks. NEM's purpose is similar to that of Ethereum in that it doesn't aim to create a currency as bitcoin does. However, it uses a more unique process to verify and process transactions, which gives "harvesting" returns to holders of more than 10,000 vested NEM tokens.

14. Tether

In the chart, you'll notice that the symbol for Tether tokens is USDT and that its value is $1.00. That's because Tether tokens are (supposedly) backed by the U.S. dollar. Because of this, Tether coins are used primarily as an intermediary to trade between cryptocurrency exchanges and are popular with traders seeking arbitrage opportunities.

15. TRON

TRON is perhaps the most specialized cryptocurrency on the list, intended to allow content creators to be compensated without having to pay any third parties. In other words, a TRON transaction could allow a user to pay for a song download and the artist could get paid quickly, without relying on the GooglePlay Store or a similar platform.

Matthew Frankel owns shares of American Express and owns Ethereum, Litecoin, and Tron tokens. The Motley Fool owns shares of and recommends Mastercard and Visa. The Motley Fool is short shares of IBM. The Motley Fool recommends American Express and Cisco Systems. The Motley Fool has no position in any cryptocurrencies mentioned. The Motley Fool has a disclosure policy.