Ethereum’s 65% Bitcoin Link Measures Risk, Not a Share of ETH’s Price
Ethereum’s widely cited “65% link” to Bitcoin remains a description of historical return behavior, not a live formula for Ether’s price. Bitwise’s March 2026 factor study analyzed 406 weekly observations beginning in May 2018, with data through February 20, 2026, and estimated that Bitcoin explained roughly 65% of the variance in ETH’s weekly returns.
Ethereum’s network continued to evolve beyond much of that sample, but technical progress has not yet supplied comparable evidence of market decoupling. An official Ethereum update published in May 2026 documents the Dencun, Pectra and Fusaka upgrades and states that standard gas was about 0.15 gwei on May 5, while daily averages during April were near 0.5 gwei.
What the 65% estimate means
The figure measures explained return variance. It describes how much of the variation in ETH’s weekly gains and losses the model could associate with Bitcoin over the sample period after considering the other variables. It does not mean that Bitcoin determines 65% of ETH’s dollar price or that every Bitcoin move produces a fixed response in Ether.
The model estimated that ETH and BTC returns moved close to one-for-one on average, but that sensitivity changed across market regimes. Bitcoin’s influence became stronger during some rallies and periods of market stress, while Ethereum-specific activity mattered more during episodes of unusually intense network use.
That distinction matters because a regression coefficient and explained variance answer different questions. The coefficient estimates the direction and size of a relationship; explained variance indicates how much of ETH’s changing returns the factor helps account for. Neither statistic is a permanent correlation reading or a reliable standalone price forecast.
The study also found that adding several other factors did not produce better out-of-sample predictions than a simpler model built around Bitcoin and ETH’s own prior returns. Its strongest conclusion is therefore about historical risk exposure, not predictive certainty: Bitcoin dominated the explanation of weekly ETH returns, while the remaining variables added comparatively limited forecasting power.
Why stronger fundamentals do not automatically lift returns
Financial conditions, active addresses and exchange-traded-product flows survived the model’s variable-selection process, although their influence varied over time. Network activity became more relevant during ecosystem booms, while fund flows appeared to provide a persistent but comparatively small marginal signal.
Network revenue was removed because it added insufficient independent weekly information under the selected specification. That finding is narrower than a claim that fees have no economic value. It means that this revenue measure did not materially improve the model after Bitcoin and the retained factors were taken into account.
Ethereum’s scaling strategy makes the distinction particularly important. Dencun created blob-based data capacity for rollups, Pectra expanded that capacity, and Fusaka introduced PeerDAS alongside further network changes. These upgrades can lower the cost of using Ethereum without producing a proportional increase in fee revenue or an immediate repricing of ETH.
Lower transaction costs can support broader usage while reducing the revenue generated by a comparable transaction. Revenue alone is therefore an incomplete adoption proxy: more affordable blockspace may benefit users and applications even when the effect on tokenholder value is indirect, delayed or offset by other market forces.
The reverse is also true. A protocol upgrade can represent meaningful technical progress without causing weekly returns to detach from Bitcoin. Evidence of decoupling would need to come from repeated market data across sustained periods, rather than from the release of an upgrade or several days of divergent price action.
Spot ether products added access, not independence
Regulated investment access changed substantially during the model’s sample. An SEC-hosted filing on spot ether products records that exchange rule changes were approved on May 23, 2024, and that the products began public trading in the United States on July 23, 2024.
Those products created an ETH-specific route for subscriptions and redemptions through traditional brokerage accounts. The factor analysis nevertheless treated their flows as a secondary influence rather than a replacement for Bitcoin’s dominant role.
Easier access should not be confused with independent price formation. Investors using spot products still operate within a crypto market shaped by shared liquidity, leverage and risk appetite, all of which can move Bitcoin and Ether in the same direction. Fund flows may affect ETH at the margin without overriding those common forces.
The result is most useful as a portfolio-risk finding
The model suggests that holding both Bitcoin and Ether historically delivered less diversification than the assets’ different technologies and use cases might imply. When one common factor explains much of ETH’s weekly movement, exposure to both assets can concentrate crypto-market risk even if their networks serve different purposes.
That does not reduce Ethereum to a permanently leveraged Bitcoin position. The rolling estimates changed with market conditions, and Ethereum-specific activity sometimes gained influence. The study also stops in February 2026, so it cannot establish the strength of the relationship after that point.
Later evidence shows that Ethereum’s infrastructure became cheaper to use and that regulated investment channels remained available. It does not provide a newer return model demonstrating durable separation from Bitcoin. The defensible conclusion is therefore precise: Bitcoin explained about 65% of ETH’s historical weekly return variance in the published model, while the question of future decoupling remains unresolved.
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