Week of 18 August 2025: Ether rises 6.88% while Bitcoin falls 3.33%
When Bitcoin and Ether finish a week in opposite directions, what can price data say about the gap opening between them, and what can it not say about who drove it?
BTC fell from 117,405.01 to 113,493.59 (-3.33%) while ETH rose from 4,472.34 to 4,780.15 (+6.88%), a gap of 10.21 percentage points. The ETH/BTC ratio gained 10.57%. Both set their largest hourly move in the same hour, 14:00 UTC on Friday 22 August, when ETH jumped 7.54%.
What the data shows. The two assets pointed different ways for the week, yet moved together hour by hour (correlation 0.84, in the close range). BTC reached its high of 117,543.75 at the week's open, Monday 00:00 UTC, and its low of 110,680.00 late on Sunday 24 August, closing in the middle third of its range. ETH fell first, to 4,060.00 early on Wednesday 20 August, then rose to 4,956.78 late on Sunday, closing in the upper third of its range. Friday 22 August was the best day for both (BTC +3.94%, ETH +14.36%), and the worst day for both was Tuesday 19 August (BTC -2.89%, ETH -5.5%). ETH swung harder: a weekly range of 22.09% against BTC's 6.2%, and realised volatility (actual swings scaled to a yearly figure) of 85.9% against 37.0%. Volume ran above the prior twelve-week average for both, 1.15 times for BTC and 1.8 times for ETH.
What it does not show. Candles record where price went, not who traded or why. Nothing here links the divergence to any event, and nothing shows whether the ETH move reflects new demand or a rotation out of BTC. The hourly correlation of 0.84 describes co-movement, not direction.
What a careful desk would check. A gap of 10.21 percentage points in one week is large relative to either return. Positions hedged on the assumption that the two assets travel together would have been tested by ETH's 7.54% hourly move in the same hour as BTC's largest move of 2.95%. A desk would ask whether its ratio limits assumed a tighter weekly gap than this.
Ether against Bitcoin. The ETH/BTC ratio gained 10.57%, and both funding averages stayed positive (BTC 0.0064%, ETH 0.0077% per eight hours). ETH's funding never turned negative, with a minimum of 0.0003%, while BTC's touched -0.0007%.
What would change this reading
- If a later week moves both assets the same way again while the ratio gives back part of 10.57%, the divergence reads as a one-week gap rather than a trend.
- If ETH holds its high of 4,956.78 while BTC stays below 117,543.75, the relative move has extended beyond one week.
- If correlation falls below the close range while funding stays positive for both, the two markets may be trading on separate positioning.
Terms
- realised volatility
- how much the price actually swung over the period, expressed as a yearly percentage
- ETH/BTC ratio
- the price of Ether expressed in Bitcoin; it rises when Ether gains on Bitcoin
- funding
- a regular payment between long and short holders of a perpetual futures contract that keeps its price near the spot price