Since the turn of the 20th century, the stock market has been the leading wealth-creating machine. Even taking into account the down years, stocks have consistently outperformed bonds and commodities over the very long term.

But in recent years, equities have been left in the dust by cryptocurrencies. For instance, Bitcoin (CRYPTO:BTC), the largest digital currency by market cap, has returned nearly 8,000,000,000% since making its debut at $0.0008 per token in July 2010.

However, it's not Bitcoin that's generating the most buzz in the crypto space of late. That honor belongs to Shiba Inu (CRYPTO:SHIB).

A Shiba Inu-breed dog sitting on grass and looking skyward.

Image source: Getty Images.

Four reasons Shiba Inu is on fire

Named after the Japanese dog breed that inspired this meme coin, Shiba Inu has returned more than 5,350,000% since it debuted on Aug. 1, 2020. SHIB's incredible success is the result of four factors.

First, Shiba Inu has found its way onto a number of popular cryptocurrency exchanges in 2021. Investors having access to buy SHIB is the first step to potentially increasing adoption.

Second, like Dogecoin, Shiba Inu is taking its bullish cues from Tesla Motors CEO Elon Musk. Musk recently adopted a Shiba Inu-breed dog named Floki and has been tweeting positively about Dogecoin and the Shiba Inu breed for months. Anytime a tweet remotely links to Shiba Inu dogs from Musk, buyers take their cue to pile into SHIB.

The third catalyst for the company was the launch of ShibaSwap in July 2021. ShibaSwap is a decentralized exchange that allows investors to stake their SHIB in order to earn interest. Although staking is nothing new in the crypto space, the ability to generate returns via staking should encourage SHIB owners to hang onto their tokens for a longer amount of time.

Fourth and finally, momentum is working in Shiba Inu's favor. When an asset rises more than 5 million percent in less than 15 months, you can bet that investors are going to pile in for fear of missing out (FOMO).

A visibly concerned person looking at a plunging chart on their tablet.

Image source: Getty Images.

Six figures that should seriously worry Shiba Inu's investors

Though it would appear SHIB has upside aplenty, a half-dozen figures would suggest that the party is about to come to a crashing halt.

1. Only 91 merchants accept Shiba Inu

One of the most glaring issues for a digital currency that's been around for less than 15 months is that it has virtually no utility outside of a cryptocurrency exchange. According to online business directory Cryptwerk, only 91 mostly obscure online companies accept SHIB as a form of payment. Considering Shiba Inu is a payment-oriented token, its lack of involvement on the payment front in the real-world is highly concerning.

2. 13-day average holding period

Something else that should seriously concern investors is the clear lack of conviction. Based on data from leading crypto exchange Coinbase, the average holding period in Shiba Inu is just 13 days. What this tells us is that a lot of people are hoping to make a quick buck in the short-term with SHIB. Conversely, it also suggests that Shiba Inu's investors may not believe in the long-term viability of the coin and are willing to jump ship on the slightest movement up or down in price.

3. 12,968 cryptocurrencies in existence (and rising)

Shiba Inu's investors are also under the constant threat of dilution -- not by other SHIB tokens, but rather by a growing number of cryptocurrency projects. CoinMarketCap.com lists 12,968 different digital currencies in existence, and this number has been growing rapidly as the total market value of cryptocurrencies has soared. Shiba Inu offers no clear competitive advantages when it comes processing transactions or via transaction fees, which is going to make it increasingly tougher for SHIB to stand out over time.

A magnifying glass set atop a financial newspaper, enlarging the words, Market data.

Image source: Getty Images.

4. 753,092 total SHIB token holders

A fourth figure to be worried about is Shiba Inu's base of roughly 753,000 token holders, per Etherscan.  Even though this figure is rising, it's a pretty small number of investors considering that SHIB has pushed above an $11 billion market cap.

For some added context, over 76 million people worldwide had a unique Bitcoin wallet on Blockchain.com, as of August 2021. Meanwhile, Ethereum (CRYPTO:ETH) has an estimated 10 million users.  The point being that major cryptocurrencies need a broad base of users to become mainstream. Shiba Inu simply doesn't have that, as of right now.

5. 82.13% of all SHIB controlled by the top 100 accounts

To build on the previous point, data from Etherscan also shows that the top 100 addresses own more than 82% of the 1 quadrillion token supply of Shiba Inu coins. Even taking into account that Ethereum co-founder Vitalik Buterin burned 90% of his SHIB holdings (well over 400 trillion tokens) by sending them to a dead blockchain address, having so many tokens in the proverbial hands of so few investors compromises the idea of Shiba Inu being a decentralized cryptocurrency. 

Even more worrisome, these remaining SHIB whales have the potential to crater the token price if they decide to sell. For instance, 50.7 trillion SHIB tokens that Buterin didn't burn were donated to the India COVID-Crypto Relief Fund. To best utilize this donation, these tokens are going to be sold. If and when these large owners bow out, remaining holders are going to feel a pinch.

6. A 5,350,880% gain in under 15 months

The sixth and final figure that should terrify Shiba Inu investors is its 5,350,880% gain in less than 15 months. While this jaw-dropping gain is precisely what's inspiring the FOMO surrounding this digital currency, history is quite clear that short-term gains of this magnitude rarely, if ever, hold up. Even Bitcoin's gargantuan gains have come on the back of multiple pullbacks of at least 80%.

History is most definitely not Shiba Inu's friend.

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.