Daily research · Big market days · written
What does Bitcoin do the day after Ether rises 4% or more?
Short answer
Across 475 cases since 2017, the typical move for Bitcoin the day after Ether rises 4% or more was −0.36%. It ended lower 56% of the time. One case in 10 did better than +3.9%, one in 10 worse than −4.0%. Out of sample, calls like it showed no clear edge.
Typical move
−0.36%
the next day, the middle case
How often
56%
it ended lower
Best 1 in 10
+3.9%
or better
Worst 1 in 10
−4.0%
or worse
Cases
475
2017-2026, on 475 days
Higher 44% of the time against 53% on ordinary days (456 days compared): higher less often than on ordinary days.
Share on Xcopy link§ 01 · The pattern475 cases
The pattern, exactly
as of · the rule, the data, the dates
A case is a day Ether closed 4% or more above the day before, and the move that counts is Bitcoin's.
Each of the 475 moves is measured from the close of the day it happened to the close 1 day later.
In our data that gives 475 measured cases on 475 separate days, from Aug 21, 2017 to Sep 21, 2026; the numbers were written on Oct 7, 2026.
§ 02 · Why it might work
Why it might work
as of · the idea traders have in mind, not a promise
Ether's big up days usually come with risk appetite returning to DeFi and the wider altcoin market. Traders watch whether that appetite carries on over the next days or fades once the move is priced in.
That is the reasoning behind watching Ether's 4% jumps; whether it held over our 475 cases since 2017 is what the next sections measure.
§ 03 · How we tested it
How we tested it
as of · our own closes, against ordinary days
- Every one of the 475 cases is measured from the close of the day it happened to the close 1 day later, on our own daily closes (UTC).
- Each case is set against Bitcoin's own ordinary days (1-day moves starting in the 365 days before it, at least 90 of them), and 456 of the 475 days had that many to compare.
- No two cases share a day, so each of the 475 days counts once.
- Out of sample: each calendar quarter, the lab re-ran its coin-by-coin search on the data before that quarter only, then scored every call the proven drivers of this kind made in the quarter after, against how often the same side won on any day of the same coin's quarter.
§ 04 · Results140 up · 177 down
Results
as of · every past case, Aug 21, 2017 to Sep 21, 2026
A day later, the middle case stood at −0.36% and the average day at −0.25%; 140 cases ended up, 177 down and 158 sideways (within ±1.0%).
ended up (140)ended down (177)sideways, within ±1.0% (158)each line one real case · past cases, not a projection
1, 7 and 30 days against ordinary days
| After | Cases | Typical move | Typical, ordinary days | Higher | Higher, ordinary days | Against ordinary days |
|---|---|---|---|---|---|---|
| 1 day this post | 475 | −0.36% | +0.13% | 44% | 53% | higher less often than on ordinary days |
| 7 days | 250 | −0.38% | +0.61% | 48% | 54% | higher less often than on ordinary days |
| 30 days | 88 | −0.48% | +2.8% | 46% | 55% | no clear edge over ordinary days |
At the other horizons: 7 days, typical −0.38% over 250 cases; 30 days, typical −0.48% over 88 cases.
By year, the typical move ranged from −0.52% in 2018 to +0.20% in 2017; 9 of 10 years leaned the same way as the whole.
Year by year
| Year | Cases | Typical move | Higher | Lower |
|---|---|---|---|---|
| 2017 | 32 | +0.20% | 50% | 50% |
| 2018 | 65 | −0.52% | 40% | 60% |
| 2019 | 53 | −0.03% | 49% | 51% |
| 2020 | 69 | −0.17% | 48% | 52% |
| 2021 | 87 | −0.36% | 45% | 55% |
| 2022 | 48 | −0.28% | 42% | 58% |
| 2023 | 23 | −0.40% | 39% | 61% |
| 2024 | 32 | −0.33% | 44% | 56% |
| 2025 | 44 | −0.34% | 43% | 57% |
| 2026 | 22 | −0.48% | 32% | 68% |
The latest 10 cases
| Day | What happened | 1 day | 7 days | 30 days |
|---|---|---|---|---|
| Ether +5.0% that day | −0.47% | −3.6% | open | |
| Ether +6.7% that day | +0.45% | +4.0% | open | |
| Ether +4.8% that day | −2.0% | −5.8% | +4.3% | |
| Ether +8.1% that day | −1.6% | −0.63% | +3.6% | |
| Ether +17.5% that day | +5.3% | +14.0% | +16.7% | |
| Ether +4.3% that day | −2.5% | −2.8% | +20.1% | |
| Ether +6.5% that day | −0.44% | +2.3% | −2.4% | |
| Ether +5.7% that day | +1.7% | +2.7% | +2.1% | |
| Ether +4.1% that day | −0.99% | −3.5% | −2.4% | |
| Ether +7.7% that day | −0.39% | +3.8% | +0.05% |
Source: our daily closes and our dated events, measured on .
§ 05 · Out of sampleno clear edge out of sample
Out of sample
as of · calls like it, scored on data they never saw
Out of sample, calls made from Ether's 4% jumps showed no clear edge: right 56% of 43 calls since 2023, against 51% for that side on any day (Oct 23, 2023 – Sep 21, 2026).
The bar to earn a side: right more often than that side won on any day, on 100+ scored calls over 60+ separate days, with an average move its way above 0%; the share above is that record's, not the in-sample rate of the 475 cases here.
§ 06 · Verdict
Verdict
as of · plain, with the caveats
In our data Bitcoin ended higher less often than on ordinary days (44% against 53% over 456 days), and both halves of the history lean the same way.
A typical −0.36% hides a wide spread: one case in 10 was beyond +3.9% and one in 10 beyond −4.0%.
Out of sample, calls like it showed no clear edge (right 56% of 43 calls since 2023, against 51% for that side on any day).
Markets change, so what Ether's 4% jumps did from 2017 to 2026 can stop working.
§ 07 · Questions
Questions
as of · answered from the numbers above
- Did Bitcoin usually end lower the day after Ether rises 4% or more?
- In 56% of 475 cases from Aug 21, 2017 to Sep 21, 2026.
- Measured the scoreboard's way, day by day, the share higher was 44% against 53% on Bitcoin's own ordinary days.
- What was the typical move?
- The middle case moved −0.36% the next day.
- The best 1 in 10 reached +3.9% or more and the worst 1 in 10 −4.0% or less.
- Can you trade on this?
- Not on its own: over 475 cases it shows higher less often than on ordinary days, and out of sample, calls like it showed no clear edge (right 56% of 43 calls since 2023, against 51% for that side on any day).
- The −0.36% typical move is the past's, and a past pattern can stop working.
- When was the latest case?
- The latest was on Sep 21, 2026: Ether +5.0% that day.
- A day later the move was −0.47%.
- Did it work the same every year?
- No. The typical move was +0.20% in 2017 (32 cases) and −0.52% in 2018 (65 cases).