Week of 21 July 2025: both assets rise, but Ether swings about 2.2 times as far as Bitcoin
When Bitcoin and Ether both close a week higher but their weekly ranges differ by more than twice, what does the week say about relative risk, and what does it leave unanswered?
BTC rose from 117,265.11 to 119,415.55 (+1.83%) and ETH from 3,756.69 to 3,872.1 (+3.07%). ETH swung through a 10.76% range against BTC's 4.82%, and its realised volatility reached 66.2% versus 31.7% for BTC. ETH closed at 98.0% of its weekly range, near the top.
What the data shows. BTC set its high of 120,247.8 at 23:00 UTC on Tuesday 22 July and its low of 114,723.16 at 07:00 UTC on Friday 25 July, so the high came first. ETH reversed that order: its low of 3,502.85 came at 07:00 UTC on Thursday 24 July, its high of 3,879.82 at 22:00 UTC on Sunday 27 July, and the close sat at 98.0% of the week's range. ETH outperformed BTC by 1.24 percentage points and the ETH/BTC ratio (Ether priced in Bitcoin) gained 1.22%. The two moved together closely (hourly correlation 0.76). Volume was above the prior twelve-week average for both: 14.48 billion dollars for BTC, 1.15 times normal, and 18.01 billion for ETH, 1.6 times normal. ETH's largest hourly move, +2.88% at 14:00 UTC on Thursday 24 July, came in the middle of the UTC day; BTC's largest was only -1.08%, at 14:00 UTC on Friday 25 July.
What it does not show. These candles record prices and sizes of moves, not who traded or why. The gap between a 31.7% and a 66.2% realised volatility (actual past swings scaled to a yearly figure) does not say whether traders treated ETH as riskier or simply reacted to it more.
What a careful desk would check. A position sized on BTC's 4.82% weekly range would have met a 10.76% range in ETH during the same week. A desk would compare its stop distances and margin buffers with ETH's 2.88% hourly move, not with BTC's 1.08%.
Funding. BTC funding was flat at 0.01% per eight hours across the week. ETH averaged 0.0099% and never fell below 0.0089%. Both positive, so long holders paid short holders.
What would change this reading
- If a later week closes below this week's ETH low of 3,502.85, the Sunday high of 3,879.82 reads as a peak rather than a pause.
- If BTC's weekly range stays near 4.82% while ETH's stays near 10.76%, any hedge sized on BTC alone stays too small for ETH.
- If the ETH/BTC ratio keeps rising past this week's 1.22% gain, Ether's outperformance is becoming a trend rather than one week's difference.
Terms
- realised volatility
- how much the price actually swung over the week, expressed as a yearly percentage
- ETH/BTC ratio
- the Ether price measured in Bitcoin, showing which asset gained against the other
- correlation
- how closely two prices moved together hour by hour, running from -1 to 1