FREE WORKSHEET · 03 / 04
Change the window.
Recheck the story.
Try one complete exercise from Reading crypto risk. Compare the same historical BTC/ETH question across three sample windows, then write down what the evidence can—and cannot—support.
Worksheet 03 · Sample sensitivity
Change the window.
Recheck the story.
Use the free study or notebook for the inputs.
In the notebook, select 2024, then 2025, then the full sample. Or use the article’s calendar-year results. Do not average the yearly statistics to fill the combined row.
The question is whether adding ETH to BTC changed the risk comparison in this fixed historical sample. Keep the return frequency, benchmark and drawdown definition visible while you work.
Sample: Coinbase Exchange USD spot candles, 31 December 2023 through 31 December 2025 UTC. There are 731 paired daily returns. This is a historical exercise, not a signal or forecast.
Tail rule
Select the lowest ceil(0.05 × N) BTC returns.
- 2024
- N = 366
- 2025
- N = 365
- Combined
- N = 731
“Ceil” rounds up to the nearest whole number.
| Window | BTC volatility | Mix volatility | BTC drawdown | Mix drawdown |
|---|---|---|---|---|
| 2024 | ||||
| 2025 | ||||
| 2024–2025 |
How many BTC tail days should each window contain?
Apply the stated rule to each value of N.
Why do the annual tail counts not add to the combined count?
ETH fell on 36 of the full sample’s 37 BTC tail days. Is 36/37 a future probability? Explain.
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This is the complete free exercise. The proposed US$19 workbook adds three more worksheets, separate worked answers, a glossary, a reusable review checklist and the full source/reproduction appendix. Those paid pages are not included or linked from this preview.
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Keep the evidence open.
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