What happened

It's been another solid day in the crypto world, with headlines that the aggregate value of all cryptocurrencies has once again passed the $1 trillion threshold, bolstering investor confidence in this sector.

This surge higher has been driven, in large part, by recent moves in Bitcoin (BTC 0.01%), Ethereum (ETH 0.31%), and Cardano (ADA -0.11%). As of 10:15 a.m. ET, these three top-10 tokens were up 4.1%, 9.1%, and 9.4%, respectively.

While Bitcoin's solid momentum over the past week, fueled by what appears to be renewed bullish sentiment and strong demand for digital currencies, is garnering headlines, it's Ethereum's outsize moves higher that have grabbed most investors' attention. Last Thursday, Ethereum started rising on news that a tentative date of Sept. 19 has been set for "the merge," which will combine Ethereum's mainnet and Beacon Chain, creating a proof-of-stake blockchain. Since Thursday morning, Ethereum has surged more than 35% at the time of writing.

Cardano appears to be benefiting from the enthusiasm around Ethereum's upcoming merge as the former prepares for its Vasil hard fork, which will bring a number of improvements to Cardano's blockchain. This hard fork had been delayed, similar to Ethereum's merge, which led to earlier concerns. However, with more optimism than pessimism today, investors appear to be taking a more positive stance on network upgrades to start the week.

So what

The upgrades underway for Ethereum and Cardano are a source of significant uncertainty for investors. There's always a chance something will go wrong, and value could be destroyed in the process of making improvements. With bearish sentiment prevailing lately, investors appear to increasingly be erring on the side of caution, waiting for concrete evidence everything will be OK before jumping in.

While those on Ethereum's developer team, including Ethereum founder Tim Beiko (who initially put the Sep. 19 date out there), have made sure to refrain from providing a "hard" date, investors now have a rough timeline for this catalyst. Other positive factors, such as the narrowing of the spread between staked Ether and Ether, suggest investors are providing significant credence to the idea this merge will take place before the end of Q3.

Now what

The next few months are shaping up to be volatile ones for these top crytpo projects. These various upgrades, previously seen as both catalysts and potential sources of uncertainty, are once again being viewed with a positive lens. That means that, right now, Ethereum's merge and Cardano's Vasil hard fork are the bullish catalysts investors have been hoping for.

That said, whether this momentum can be carried forward remains to be seen. This bear market is a doozy, and overall sentiment in the crypto sector continues to reflect extreme fear. Until that changes, it's going to be hard for such momentum-driven rallies to hold steady. Accordingly, investors may want to exhibit caution before adding aggressively to these top growth-oriented projects.