Cryptocurrencies have been the talk of 2021 for their outsized price gains on one hand, and questionable utility on the other. Some of the most famous investors in the world are divided on the subject. While some famous names are big crypto bulls, Warren Buffett has weighed in to tell the world he "never will" own any cryptocurrency.

But tell that to the select group of speculators who have done marvelously well owning tokens like Shiba Inu (CRYPTO:SHIB), which has risen 49,000,000% since January. In other words, an investment as small as $3 in the tokens coming into 2021 -- had you held on -- would have made you a millionaire today.

Two smiling friends walking down the street with shopping bags on their arms.

Image source: Getty Images.

However, Shiba Inu is proving to be little more than the second coming of Dogecoin (CRYPTO:DOGE), which was originally created as a joke. Enthusiastic traders have tried to send both tokens "to the moon" in their attempts to replicate the success of Bitcoin (CRYPTO:BTC), which now has a market value of over $1 trillion.

Limited adoption could mean weak performance from here

Unfortunately, the latest hype cycle appears to have stalled: Shiba Inu is down 57% from the all-time high it touched in October, and Dogecoin is down a whopping 72% from its peak. Traders picking up these tokens now in the hopes of becoming rich are liable to be disappointed. 

Part of the reason is a notable lack of adoption of tokens by businesses and consumers. If people can't easily spend their tokens in everyday life, they have little reason to acquire them, which leaves pure speculation as their chief use-case. And the hope that someone will later come along who's willing to pay a higher price than they did for the tokens may not be enough to keep demand strong or prices rising.

Token

Number of Merchants Accepting This Token as Payment

Bitcoin

7,610

Dogecoin

1,958

Shiba Inu

369

Data Source: Cryptwerk, as of November 2021. 

Based on the recent performance of these tokens, and the lack of signs on the horizon that they'll be widely adopted as means of transacting business, long-term investors might do well instead to stick to some proven stocks in the fintech space. 

Payment giants Square (NYSE:SQ) and Fiserv (NASDAQ:FISV) have over 100 million users combined, which means they're crushing all cryptocurrencies in both transaction volume and adoption. 

The case for Square

Square was once simply a digital payments hardware company, helping small businesses facilitate credit card transactions with its iconic square electronic readers. But it's now one of the biggest innovators in consumer finance, with its CashApp smartphone platform boasting over 40 million monthly active users.

CashApp is similar to an online banking product, except less complicated. It allows consumers to make instant peer-to-peer transactions, and purchase products online or in-store through its branded Visa card. Its investing platform also provides users with access to stock market and cryptocurrency trading, and since it's all hosted within the CashApp ecosystem, moving money around is seamless. 

Cryptocurrency fans might be pleased to know that more than 59% of Square's revenue so far this year has come from Bitcoin transactions on the CashApp platform. The company earns a very small gross margin on these transactions -- just 2% -- so Bitcoin is not the biggest driver of Square's earnings growth, but it does give investors some exposure to the space attached to a high-quality payments business.

That said, there could be a new, significant driver of growth for CashApp. Earlier this year, Square announced it was buying "buy now, pay later" leader Afterpay for $29 billion. While Square already offers loans to businesses through Square Loans, it will integrate Afterpay into CashApp so that it can finance consumer purchases too, adding a new revenue stream to its business.

Bitcoin might not have widespread adoption on its own, but Square offers a great long-term opportunity to own a platform that could help grow the cryptocurrency's footprint in the world of everyday commerce. 

A customer making a contactless payment to the barista in a small goods store.

Image source: Getty Images.

The case for Fiserv

If you've never heard of Fiserv, that may be because it's not a consumer-facing brand. It operates behind the scenes in the payments industry, but it has touch points with every household in America. It achieves this through the 10,000 banks and financial institutions it serves, in addition to 6 million businesses globally.

The company operates in three main areas. Its merchant acceptance segment hosts the Clover point-of-sale technology, which helps businesses accept payments from customers. Clover is one of Fiserv's fastest-growing components, increasing its gross payment volume by 47% year over year in the third quarter alone.

The company also serves banks in two key ways. First, it facilitates instant payment processing, a service that is in high demand in modern commerce -- and it does so to the tune of 12,000 transactions each second. Second, it provides the financial technology necessary for banks to offer online banking portals to their customers. Around 100 million customers are using Fiserv-powered internet banking, even if most of them don't realize it.

In total, Fiserv has over 1.4 billion accounts on file globally, which gives it a scale most other payment giants may never reach -- let alone most cryptocurrencies.

Yet the best thing about Fiserv might be its stock price. With expectations that it will earn $5.58 per share in 2021, it's trading at a price-to-earnings multiple of just 17. That's significantly cheaper than the S&P 500 index, which is trading at a multiple of 28. While analysts don't anticipate lightning-quick earnings growth next year, 16% is likely enough at this price to warrant steady long-term share price growth.

After all, when weighing stocks versus mostly speculative cryptocurrencies, investment cases are as much about staying power over the long run as they are about actual returns. 

This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.