If you had invested less than $2,000 in Bitcoin (BTC 5.29%) when it first began trading, you'd now be a millionaire. That's assuming that you held onto your digital coins, of course.

Buying Dogecoin (DOGE 5.50%) could also have made you a millionaire. An investment of less than $2,800 in the digital tokens in late 2013 would now be worth $1 million. 

But, as the old saying goes, that's all water under the bridge. Could Bitcoin and Dogecoin still be millionaire-makers?

Two people looking at an image of a Bitcoin symbol in the middle of a circuit diagram.

Image source: Getty Images.

Keys to their success

To determine the likelihood of future success, it's important to understand the keys to the past success of Bitcoin and Dogecoin. There's at least one common denominator for the two cryptocurrencies -- their novelty.

Bitcoin was the world's first cryptocurrency. The concept of a blockchain (and even the word "blockchain" itself) didn't exist before Bitcoin. 

Dogecoin had a different kind of novelty factor. It was created as a fun alternative to Bitcoin. The Shiba Inu dog on the Dogecoin logo became a popular internet meme. Tweets and support from Elon Musk contributed heavily to Dogecoin's popularity. Musk personally owns Dogecoin as well as Bitcoin and Ethereum (ETH 3.41%).

Novelty only goes so far, though. Both cryptocurrencies also gained adoption beyond just trading. Bitcoin is by far the biggest winner on this front. It's accepted as a form of payment by more than 15,000 businesses. Some investors view it as an inflation hedge.

Dogecoin isn't as widely accepted by merchants as Bitcoin. However, the cryptocurrency has picked up more support in recent months. It's also used for tipping on Reddit and Twitter

Current and future challenges

The current and future challenges for Bitcoin and Dogecoin directly relate to the keys behind their past success. Neither are the shiny new coins that they once were. The novelty factor has waned for both.

Sure, Bitcoin remains the biggest cryptocurrency based on market cap. DogeCoin ranks in the top 10. However, there are plenty of digital coins vying to become "the next Bitcoin." And DogeCoin faces several rival meme coins. Shiba Inu supporters even call the token the "Dogecoin killer." 

More importantly, the real-world utility of Bitcoin and Dogecoin is being surpassed. For example, Ethereum's blockchain paved the way for non-fungible tokens (NFTs) and a wave of new cryptocurrencies. Many of the most popular digital coins on the market today are built on the Ethereum platform. 

There could even be a challenge to Bitcoin's status as the best cryptocurrency for hedging against inflation. A recent study conducted by researchers at the University of Sydney and Macquarie University suggests that Ethereum could be an even better inflation hedge than Bitcoin.

Still millionaire-makers?

Neither Bitcoin nor Dogecoin has as easy of a path going forward as they've enjoyed in the past. Does that mean that the two cryptocurrencies aren't still millionaire-makers? Not necessarily.

Any asset at least theoretically holds the potential to make $1 million. You might have to invest an extraordinarily large initial amount and/or have to wait a really long time for it to happen, though.

From that standpoint, both Bitcoin and Dogecoin could still be millionaire-makers over the long term. However, don't count on either of the cryptocurrencies to grow an initial investment of less than $2,800 into $1 million within the next decade or even the next 30 years.