Bitcoin Fails in August, Ethereum Shines: Is the Money Flow Reversing?

In the traditional financial world, every summer, people often refer to the old saying: "Sell in May and go away" – sell in May and go on vacation. Although this seasonal signal has almost lost its value today, it is still often brought up for discussion. The cryptocurrency market, which has only existed for just over a decade, is also beginning to form its own "seasonal signals", notably the perspective that August is often a difficult period for prices. Bitcoin loses momentum, wiping out the summer breakout. This year has shown that. Despite many favorable factors such as: The flow of money continues to pour into spot ETF funds, Fed Chairman Jerome Powell shifts his tone from "hawkish" to "dovish", Bitcoin hits a new all-time high, but within a few weeks, BTC has dropped 8% in August, currently trading around 108,000 USD, which is about 13% lower than the peak of 124,000 USD set on August 13. This means that the entire upward momentum from late spring to summer has been wiped out, and the price is currently even lower than the level recorded on Memorial Day (109.500 USD). Ethereum goes against the trend, attracting a strong influx of capital. In stark contrast to Bitcoin, Ethereum (ETH) is shining. In just August, ETH increased by as much as 14%, outperforming BTC by 2,200 basis points. This comes from the surge of capital flowing into companies holding ETH and spot ETH ETFs. While Bitcoin ETF funds have stagnated after their initial hype, Ethereum ETFs have seen a boom. According to Bloomberg data (James Seyffart), in just the month of August up to August 28, the ETH ETF attracted a net of 4 billion USD, while the BTC ETF only had 629 million USD. Given that the market capitalization of ETH is only about 500 billion USD (which is 1/4 compared to Bitcoin's 2.1 trillion USD), this figure is even more remarkable. This reflects a reality: in the context of tight U.S. monetary policy, tighter fiscal policy due to high tariffs, global capital flows are limited. And in August, the capital flow chose Ethereum, seemingly directly "siphoning" Bitcoin. September harvest season: Be cautious but don't be overly obsessed. If August has been harsh, the statistics show that September is even worse for Bitcoin. According to data from Glassnode, over the past 12 years (2013–2024), BTC has dropped in price in 8 out of 9 months, with an average decrease of -3.8%. The rare increases have also been very modest. However, there are two points to note: 12 data points are too few to be considered a definitive rule. During the period from 2013 to 2019, Bitcoin was still just a "fringe" asset, lacking an ETF and not attracting large institutional capital flows as it does today. Therefore, historical numbers may not accurately reflect the current reality. Conclusion August has proven that Ethereum is increasingly becoming a real competitor to Bitcoin, at least in the eyes of institutional capital flows. The fact that the ETH ETF is attracting capital multiple times more than the BTC ETF indicates a shift in market structure. Although seasonal signals like "September is on fire" may be indicative, investors should not absolutize them. Instead, monitoring ETF capital flows, monetary policy, and macro movements are the determining factors for the trend of the cryptocurrency market in the last months of 2025.