Ethereum and Solana: Recent Gains and Upcoming Changes In September
Ethereum and Solana both surged last week, but one cryptocurrency is heading into a major network upgrade while the other is still waiting on a test run. The gap between their roadmaps could determine which rally has real staying power.
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Last week, both Ethereum (CRYPTO:ETH) and Solana (CRYPTO:SOL) posted strong gains, with Ethereum up 10.2% and Solana up 15.5%. As of September 25, Ethereum is trading at $2,694, while Solana is at $117. However, both cryptocurrencies are still down for the year, with Ethereum down about 9% and Solana down by approximately 5%. With these recent rallies, the question arises: which cryptocurrency has stronger support behind its gains?
Solana’s Alpenglow Upgrade Is Scheduled for Mainnet on September 28

Solana’s upcoming upgrade, called Alpenglow, is set for September 28. This upgrade will revamp how Solana’s validators—the computers that confirm transactions—achieve consensus on block finality. Alpenglow will replace the current protocol, TowerBFT, with a new voting protocol called Votor.
This change aims to reduce transaction finality time from around 12.8 seconds to about 150 milliseconds. These speed improvements will let payment and trading applications treat transfers as nearly instant.
Additionally, the Alpenglow upgrade will enhance network reliability. Under the current system, Solana stops finalizing blocks if more than a third of staked SOL goes offline. Earlier this year, a routing failure caused 28.8% of staked SOL to go offline, putting the network at risk. With Alpenglow, this threshold will increase to 40%, making the network more robust against such failures.
The developer behind Solana’s main validator software, Anza, has met every milestone on time or with minimal delay. The Alpenglow code has already been running on the main network in a non-active state since September 18. However, Anza has described the September 28 launch date as tentative, since the upgrade will only activate once 95% of staked SOL is running the new version.
Ethereum’s Glamsterdam Upgrade Has Slipped to the Fourth Quarter

In contrast, Ethereum’s next upgrade, known as Glamsterdam, has faced multiple delays. Originally scheduled for June 2026, it was pushed back to the third quarter and is now targeted for the fourth quarter. The next crucial step is a test run on the Sepolia test network, scheduled for October 6. This test allows developers to practice changes before they go live on the main network.
For Ethereum holders, this test run is not the same as a launch. If the Sepolia run goes smoothly, it keeps the fourth-quarter target alive. However, any further delays could push the upgrade into 2027.
Solana Funds Kept Taking In Money as Ethereum Funds Had a $140 Million Outflow Week

Looking at investment trends, U.S. spot Solana ETFs have been on an upward trajectory, taking in new funds for 12 consecutive weeks and now holding about 2.6% of all circulating SOL. In contrast, Ethereum has faced challenges, experiencing a $140 million outflow in one week this September, although it has since returned to positive territory.
Solana’s fund inflows have slowed significantly, with weekly inflows dropping from about $154 million earlier in September to just $6 million, but funds are still purchasing at a much slower pace. Furthermore, Solana currently hosts around $465 million in tokenized stocks, a business the SEC opened to more venues on September 17.
Which Rally Has Stronger Support, Ethereum’s or Solana’s?
Given the circumstances, Solana’s rally appears to have stronger support. It is the only one of the two with an upgrade scheduled in September—one that not only enhances finality to about 150 milliseconds but also increases network resilience. In contrast, Ethereum’s next step involves a test run, and its main upgrade has faced multiple delays.
However, the exact launch date for Alpenglow isn’t set in stone. While Anza has described September 28 as tentative, if the upgrade proceeds successfully, Solana holders will see a definitive upgrade backing their recent rally. If there are setbacks or if Solana’s value dips below $100 (about 15% lower than its current price of $117), the fundamental support behind Solana’s lead may weaken just before the upgrade arrives.
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