TLDR
- Ethereum has gained 25% since August 1st, trading above $4,700 as of late August 2025
- Historical data shows ETH typically falls in September after August gains, with average losses of 6.42% since 2016
- Spot Ethereum ETFs attracted nearly $3 billion in net inflows during August 2025
- Corporate treasuries now hold over $17 billion in ETH, with BitMINE accumulating $6.6 billion alone
- Previous August-to-September patterns: 2017 (+92% then -21.65%), 2020 (+25% then -17%), 2021 (+35% then -12.55%)
Ethereum has delivered strong gains throughout August 2025, climbing 25% from its opening price of $3,807 to trade above $4,700. The second-largest cryptocurrency crossed new highs above $4,867 following dovish comments from Federal Reserve Chair Jerome Powell at the Jackson Hole symposium.
Powell’s hints at potential interest rate cuts next month have been viewed as bullish catalysts by crypto markets. However, historical data presents a concerning pattern for Ethereum holders as September approaches.
Since 2016, September has been Ethereum’s worst-performing month with average losses of 6.42%. The pattern becomes more pronounced following strong August performance, with only three instances of August gains since 2016 – each followed by September declines.
Institutional Inflows Drive August Rally
Spot Ethereum ETFs have attracted nearly $3 billion in net inflows during August 2025 alone. This compares to approximately $1.2 billion in net outflows from spot Bitcoin ETFs over the same period, showing a shift in institutional preference.
$ETH ETF inflow + $523,900,000 yesterday.
Ethereum ATH this week. pic.twitter.com/oKdRDW0EoI
— Ted (@TedPillows) August 13, 2025
Corporate treasury adoption has reached new heights, with companies collectively holding over $17 billion in ETH reserves. BitMINE Immersion Technologies, led by Tom Lee, has accumulated the world’s largest corporate Ethereum treasury at $6.6 billion, surpassing major investment firms like ConsenSys.
The company’s recent $45 million ETH purchase brought their total holdings to $7 billion. This institutional accumulation has helped lock up liquid supply and supported price momentum throughout the month.
Bitcoin dominance has fallen 5.88% over the past 30 days to 58.19%. Market participants typically view this decline as capital rotating into alternative cryptocurrencies beyond Bitcoin.
On-chain factors have also contributed to the rally. DeFi activity remains strong while protocol upgrades like Pectra have reduced liquid supply and encouraged longer-term holding behaviors.
Historical September Weakness Pattern
The September weakness pattern appears consistent across multiple cycles. In 2017, Ethereum surged 92.86% in August before dropping 21.65% the following month after China announced ICO bans.
The 2020 cycle saw a 25.32% August gain followed by a 17.08% September pullback. Most recently in 2021, Ethereum climbed 35.62% in August before declining 12.55% in September.
Crypto traders have highlighted this seasonality on social media platforms. One trader noted that ETH seasonality in September during post-halving years is typically negative, questioning whether 2025 will break the pattern.
Bullish Forecasts Despite Seasonal Headwinds
Not all analysts expect September weakness to materialize this year. Standard Chartered Bank has issued a forecast for ETH to reach $7,500 by year-end 2025, with longer-term targets of $12,000 in 2026 and $18,000 by 2027.
Tom Lee told CNBC on August 13 that he expects Ethereum to “keep charging ahead” with ETF inflows and institutional adoption pushing prices above $7,000. His comments came as BitMINE continued building its massive ETH position.
The presence of spot ETH ETFs and corporate treasury adoption represents new market dynamics not present during previous August rallies. These institutional flows could potentially alter historical seasonal patterns.
September portfolio rebalancing and tax-related selling typically contribute to seasonal weakness after summer rallies. Whether these factors will outweigh institutional buying pressure remains to be seen as the month approaches.
