When most investors think of investing in crypto, they probably think of popular cryptocurrencies such as Bitcoin or Ethereum. And for good reason -- these two cryptos account for a whopping 70% of the entire market capitalization of the crypto market.

But there's one overlooked area of the crypto industry that has started to gain momentum recently, and that's stablecoins. The two biggest stablecoins -- Tether and USD Coin (USDC -0.01%) -- together have a combined market value of more than $100 billion, or about 10% of the entire market cap of the crypto industry. For that reason alone, stablecoins need to be on your radar. But there's also a potential hidden growth opportunity that makes them even more intriguing.

What are stablecoins and why do they matter?

Stablecoins are cryptocurrencies, and you invest in them the same way that you invest in Bitcoin or Ethereum. What makes them unique is that their value rarely changes because they are typically pegged 1-to-1 to the U.S. dollar and are fully backed by dollar deposits or cash equivalents. Thus, they are almost always priced exactly at $1. (In a worst-case scenario, though, stablecoins can lose their peg, which happened in a number of dramatic cases during the crypto collapse of 2022.)

The best way to think about stablecoins is that they are "digital dollars" that enable investors to move between traditional financial markets and the crypto market. They have a handful of different uses. You could use them to pay for purchases, for example. The fact that their value is (theoretically) unwavering makes them very useful for this purpose. If you know that a purchase costs $25, for example, then you know that it also costs 25 USD coins. This makes them very consumer-friendly, because consumers think in terms of dollars.

So, at this point, you're probably wondering: If the value of a stablecoin is always $1, then how is this a profitable growth opportunity? Well, I'm glad you asked. The way to make money in stablecoins is by investing in companies that are embracing them as part of their core business models. These companies recognize that the dollar is going digital, and that the future of money probably involves stablecoins. Thus, if you can get in early on these growth opportunities, it could prove very profitable over the long haul.

Three examples of companies using stablecoins

To bring this concept to life, I've picked out three companies that offer different twists on the stablecoin investment thesis: PayPal Holdings (PYPL 2.90%), Visa (V -0.23%), and Shopify (SHOP 1.11%).

Investor surprised by news on smartphone.

Image source: Getty Images.

First up is PayPal, which became the first major financial institution ever to issue a stablecoin. In August, PayPal shook up the financial industry with the news that it was launching PayPal USD, a stablecoin pegged 1-to-1 to the U.S. dollar and 100% backed by U.S. dollar deposits, short-term U.S. Treasuries, and cash equivalents.

PayPal envisions three key use scenarios for this new stablecoin. It can be used to transfer funds between a PayPal account and an external blockchain wallet. It can be used to make peer-to-peer payments. And it can be used to pay for purchases. This stablecoin has been around for less than three months, but you can already see how PayPal is starting to think about the future of money.

Next up is Visa, which partnered with Solana on a new stablecoin payment project at the beginning of September. This project will enable merchants to accept USD Coin as a form of payment, and all transactions will be settled on the Solana blockchain rather than the Visa network. This project recognizes that some customers prefer to pay with crypto and some merchants prefer to get paid in crypto. If you've ever heard a store owner complain about credit card fees, it's easy to see why stablecoins could be attractive to some merchants.

And finally there's Shopify, which recently added stablecoin payment functionality for merchants. Basically, if you own a Shopify storefront, you can now opt to select USD Coin as a form of payment via an integration with Solana. All USD Coin transactions will then be settled on the Solana blockchain, without the need for a bank intermediary. For Shopify merchants, this might be attractive because it can eliminate bank fees, chargebacks, and hold times.

Is it too early to invest in stablecoins?

A big caveat, of course, is that it is still very early to be thinking about stablecoins as a growth investment opportunity. While stablecoins have been around since 2014, the stablecoin projects from Visa, Shopify, and PayPal are all less than three months old. So don't expect them to move the needle quite yet. After all, Visa has a market cap of nearly $500 billion, and we're far from the day when consumers routinely pay with stablecoins. 

However, it's definitely useful to start tracking the growth of stablecoins. As for me, I'm tracking PayPal's new stablecoin reports. I'm mentally noting the companies and blockchains involved in new stablecoin projects. And I'm keeping my eye on Washington, D.C., where legislators have made stablecoins an important focal point for the crypto industry. If you've ever dreamed of being early on a unique $100 billion investment opportunity, then stablecoins might be the answer.