After a months-long downturn, the crypto market is finally starting to rebound. Because prices are still relatively low, though, now is a good time to consider adding to your portfolio.

Cryptocurrency can be a tricky investment because it's largely speculative right now. Nobody knows which cryptos will succeed over the long run (or if the sector as a whole will still be around decades from now), which can make it tough to choose the right investments.

While crypto is still risky at the moment, there are a few that have some significant advantages and could make for strong long-term investments.

Blue digital piggy bank.

Image source: Getty Images.

1. Ethereum

As the second most popular cryptocurrency behind Bitcoin, Ethereum (ETH -1.55%) is a favorite among investors.

Ethereum is the largest network for decentralized applications, which can include everything from decentralized finance (DeFi) projects to non-fungible token (NFT) marketplaces. As interest in these areas continues to grow, Ethereum is becoming even more widely used.

Developers are also working on an update to the blockchain that will make it much faster and more affordable for users. This upgrade will move Ethereum from a proof of work (PoW) mining protocol to proof of stake (PoS), significantly improving its transaction times and reducing its fees.

The second phase of this update is expected to be completed sometime this year, while the final phase won't be rolled out until next year. Once it's finished, though, Ethereum could be an even stronger player in the crypto space.

2. Solana

Solana (SOL -2.54%) is one of the fastest-growing networks and had an incredible year, soaring more than 11,000% over 2021.

This crypto's biggest advantage is that it shines where Ethereum falls short. Currently, Ethereum's transaction times are extremely slow. Solana, on the other hand, is one of the fastest networks in existence, with transaction times of up to 65,000 transactions per second (compared to Ethereum's sluggish 13 transactions per second).

Once Ethereum finishes its upgrade, it may be tougher for Solana to compete. However, developers have been flocking to Solana while awaiting Ethereum's update, and there's still plenty of time for Solana to create new advantages and solidify its niche in the crypto sector.

3. Cardano

Cardano (ADA -3.91%) is similar to both Ethereum and Solana in that it's a platform for decentralized applications. Where it differs, though, is in its strategic approach to growth.

Cardano developers have carefully laid out a multistage roadmap for how the cryptocurrency will grow over time. It also uses a peer review system when rolling out updates, with each update needing approval from the team before it can be launched. In theory, this should result in more stable growth and fewer glitches with the network, which can be a major competitive advantage.

One thing to keep in mind when investing in cryptocurrency is that it isn't necessarily a zero-sum game. It's possible for multiple cryptos to succeed, even if they're similar in many ways. We're still in the early stages of the cryptocurrency movement, and as time goes on, we'll probably see each network develop more unique advantages.

Cryptocurrency can be a risky investment, because nobody knows how it will perform over time. But these three top performers are some of the strongest options right now, and they could have a chance of seeing significant growth over time.