The cryptocurrency market ran into a brick wall last November, just after leading digital currencies such as Ethereum (ETH -5.76%) and Bitcoin (BTC -4.60%) recorded what still count as their all-time highs. Today, Bitcoin trades 67% below the soaring record prices of last fall, and Ethereum has taken a 69% haircut.

At the same time, the crypto sector has started to show signs of life again. Bitcoin has gained 20% from last week's short-term lows, and Ethereum posted a 49% gain over the same period. Some lesser-known altcoins have delivered even greater weekly returns. Some cryptocurrencies are reporting significant news of their own, and others are simply bouncing back from a period of brutal market pessimism.

This recovery may or may not last. It's hard to tell what's going to happen next in the ultra-volatile crypto market. Maybe you want to pick up a few digital coins or tokens at this point, where a sense of stability meets low prices.

However, some crypto tokens are just doing a head-fake right now, and I don't expect them to deliver strong returns in the long run. In fact, I wouldn't be surprised to see them falter while the healthy core of the crypto sector executes a full recovery. In short, you shouldn't buy these cryptocurrencies in any market.

This failed token has already been replaced

The TerraUSD (USTC -8.79%) stablecoin lost its peg to the U.S. dollar in May. That failure to serve as an unshakable financial bedrock had several tragic results.

  • TerraUSD, which was supposed to be worth approximately $1 per token at all times, is now trading at $0.05 per token instead.
  • Investors, developers, and cryptocurrency enthusiasts have lost their confidence in so-called algorithmic stablecoins, backed by other cryptocurrencies and lightning-fast automatic trades instead of gold or cash reserves.
  • The token known as Terra (LUNA) at that time was swiftly replaced by a brand new blockchain, which carries on with the Terra (LUNA -11.09%) name today. The old token continues to exist under the banner of Terra Classic (LUNC -10.06%). However, that blockchain network no longer processes transactions and the decentralized finance projects that used to depend on it have moved on to the relaunched Terra ecosystem.

Strangely enough, Terra Classic still clings to life with a market cap of $697 million and an average trading volume of more than $120 million per day. The token trades at fractions of a penny, down from a peak value of $119 per token in April.

This is a dead project, already replaced by a tweaked version of the same technology platform, and nobody is working to bring it back to life. Terra Classic is not poised for a triumphant return to $100 per token, or even $1 per token for that matter. Your hard-earned money is better invested almost anywhere else, including in the relaunched Terra cryptocurrency.

This one was never a serious investment

I'm sorry if you've heard this before, but Dogecoin (DOGE -9.14%) was never meant to be a serious investment. This cryptocurrency was launched as a joke, using code from a copy-of-a-copy of the original Bitcoin system, but changed in ways that only undermine Dogecoin's viability as a long-term investment.

Chiefly, Bitcoin's software has a hard-coded limit that means no more than 21 million Bitcoins will ever exist. Dogecoin started out with a similar cap, but its founding developers removed it for the express purpose of making it worthless as an investment. Gold is expensive because there's only a limited amount of it on this planet. Bitcoin emulates that idea with its firm cap. Dogecoin threw that whole idea out the window, focusing on its dog-themed marketing image instead.

Please note that I do not include the seemingly similar Shiba Inu (SHIB -10.00%) crypto on this list of tokens to avoid at all costs. Shiba Inu was also started as a bit of a joke and comes with a similar dog-faced marketing message, but that's where the similarities end. Shiba Inu is an Ethereum-based crypto network, where all possible tokens were created at the start of the project. There is no mining, there is no inflation, and Shiba Inu could theoretically become valued for its scarcity. I'm not saying that it will, or that you should buy it today, but Shiba Inu is a more robust investment idea than Dogecoin in the long run.

I'm just letting you know that Dogecoin can't and shouldn't be taken seriously.

Don't jump on the latest hot tip

There are thousands of cryptocurrencies on the market already, and more are joining the party almost every day. Most of the new tokens will stay unknown. One day, their underlying computer networks will stop working and the value of those tokens will go to zero. It's a lot like watching penny stocks on the stock market. Most projects are bound to fail, and some of them are outright scams.

Please be careful out there, dear reader. That hot new crypto ticker that just tripled in value overnight will probably evaporate just as quickly. It doesn't matter that the token came with a cool business idea related to real estate in the metaverse, tracking diamonds from the mine to the wedding ring buyer, or managing medical records for retired Marines in Idaho. None of that matters unless the cryptocurrency is managed by a group of competent and trustworthy people, backed by a proper amount of financial assets, and finds real-world usage even in its early days.

There are too many blink-and-you-missed-it flashes in the pan to list here. The shallow end of the cryptocurrency market is not a good place to look for wealth-building investments with serious value. Established giants like Ethereum and Bitcoin will serve you better, and you can even invest in crypto-focused stocks instead of cryptocurrencies if you want to dip your toe in these risky waters with a thicker layer of regulations and fiscal safety.