Week of 18 January 2021: Bitcoin falls 9.95% while Ether gains 12.98% in the same week
When Bitcoin and Ether move in opposite directions over one week, what does the price data say about the split, and what does it leave unexplained?
BTC fell from 35,824.99 to 32,259.90 (-9.95%) while ETH rose from 1,232.50 to 1,392.51 (+12.98%), a gap of 22.93 percentage points. Both assets set their weekly low at the same hour, 01:00 UTC on Friday 22 January. The ETH/BTC ratio gained 25.47%.
What the data shows. The two assets shared a low but not a direction. BTC and ETH bottomed together at 01:00 UTC on Friday 22 January (28,850 for BTC, 1,042.31 for ETH), then split: BTC's best day was Friday (+6.78%) and it closed in the middle third of its weekly range, while ETH's best day was Sunday 24 January (+12.89%) and it closed in the upper third. Hourly correlation was 0.82, close but not tight, so the paths overlapped without matching. Both had their worst day on Thursday 21 January (BTC -13.02%, ETH -19.30%). ETH dollar volume was 2.42 times its prior twelve-week average, BTC's 1.43 times. ETH finished only 2.59% below its 52-week high; BTC was 22.18% below. ETH's weekly return ranked at the 86th percentile of the 153 weeks before it, BTC's at the 14th.
What it does not show. The data records the divergence, not its cause. An hourly correlation of 0.82 cannot say whether money moved from one asset to the other or whether separate flows met in the same week. There is no open-interest or holder data, so the split cannot be attributed to any group of traders, and nothing here indicates what followed.
What a careful desk would check. The ETH/BTC ratio rose 25.47% in one week. A desk holding both assets would see its weighting shift on its own, and would check whether that shift matches its mandate. Each asset's own largest hourly move of the week came in the same Friday stretch: BTC's -4.28% in the hour starting 00:00 UTC, the hour before its low, and ETH's +5.49% in the hour starting 01:00 UTC, at its low. A position sized before those hours faced a sharp move in each asset within two hours.
Funding. BTC funding averaged 0.0446% per eight hours, with a high of 0.1585%; ETH averaged 0.0732%, with a high of 0.1996%. Longs paid shorts on average for both assets, and the cost of staying long was higher for ETH, in line with its stronger week.
What would change this reading
- If the ETH/BTC ratio holds near its post-rise level in later weeks, this week reads as a repricing rather than a one-week swing.
- If BTC recovers towards its weekly open of 35,824.99 while ETH stalls, the split narrows and reads more as timing than direction.
- If both assets fall together in a later week, the divergence here was specific to this week rather than a lasting decoupling.
Terms
- ETH/BTC ratio
- the price of one Ether expressed in Bitcoin; it rises when Ether outperforms Bitcoin
- percentile
- the share of past weeks with a lower value; the 86th percentile means 86% of past weeks were lower
- funding rate
- the periodic payment between long and short holders of a perpetual futures contract; positive means longs pay shorts