MARA overnight gaps: Monday (Fri→Mon) vs Tue–Fri over the last ~3 years
MARA’s Monday opens are meaningfully larger. Over the past ~3 years the average absolute Friday→Monday gap was 3.11% versus 2.17% for Tue–Fri overnights — the weekend appears to compress larger, unhedgeable Bitcoin moves into Monday’s opening price. The difference is robust; the full analysis below quantifies magnitude, distribution, and statistical confidence.
I tested this by computing absolute overnight gaps from regular‑hours minute bars across the most recent 36 months and comparing the Friday→Monday distribution to other weeknights with a Welch two‑sample t‑test. Scroll down for the charts, detailed statistics, and distributional evidence that explain where the lift shows up (center, tails, and per‑weekday breakdown).
For MARA over the past ~3 years, are Monday opening gaps systematically wider than other weekdays — does a full weekend of unhedgeable Bitcoin moves get crammed into Monday's open while the stock sits closed? Thesis: the average absolute Friday-close-to-Monday-open gap runs materially larger than Tuesday-through-Friday overnight gaps, so MARA's biggest overnight risk is the weekend it can't trade.
How this was measured
Minute bars were filtered to US regular trading hours (Mon–Fri, 09:30–16:00 ET). For each session, the day’s RTH open is the first 09:30 bar’s open and the RTH close is the last pre‑16:00 bar’s close. Overnight gap for day t is open_t ÷ close_{t−1} − 1; we analyze absolute gaps. The sample is restricted to the most recent 36 months of available data. We compare the Monday (Friday→Monday) absolute gap distribution to the aggregate Tue–Fri distribution using a Welch two-sample t-test and summarize per-weekday statistics.
The key numbers
Reading the numbers
MARA's mean absolute Monday overnight gap is 0.031149 (N=143) versus 0.021675 for Tue–Fri (N=608) — about a 1.437× larger weekend jump, and the difference is statistically significant (p=0.000187).
The charts
The box plot lays out the whole distribution by weekday: Monday's mean absolute gap is 0.031149 (n=143) while the other weekdays cluster around 0.0206–0.0229. Notice the much larger upper tail on Mondays — a Monday max of 0.1896 compared with next-highest Friday max 0.149 — which shows more extreme weekend-driven openings. In short, Mondays not only sit higher on average but also produce the biggest outliers, consistent with concentrated weekend risk.
This bar chart highlights the central comparison: mean absolute gap of 0.031149 on Monday versus 0.0216749 for Tue–Fri, a mean difference of 0.009474457 and a ratio of 1.437116. The Welch t-statistic is 3.8152496 with a two-sided p-value of 0.00018697, meaning the larger Monday mean is unlikely to be random. That supports the thesis that weekend Bitcoin moves tend to be compressed into Monday's open more than a typical weekday overnight.
Weekday summary of absolute overnight gaps
| Weekday | N | Mean | Median | Std |
|---|---|---|---|---|
| Monday | 143 | 0.0311 | 0.0258 | 0.028 |
| Tuesday | 156 | 0.0215 | 0.0161 | 0.0206 |
| Wednesday | 153 | 0.0217 | 0.0179 | 0.0196 |
| Thursday | 148 | 0.0229 | 0.0182 | 0.0228 |
| Friday | 151 | 0.0206 | 0.0166 | 0.019 |
The takeaway
Yes — Monday (Friday→Monday) opens are meaningfully larger. The average absolute Friday→Monday gap is 3.11% versus 2.17% for Tue–Fri overnights. That’s a mean difference of +0.95 percentage points and roughly a 1.44× lift (Mon/Tue–Fri = 1.437), so a full weekend of unhedgeable Bitcoin moves tends to be compressed into Monday’s open. This result is statistically strong: 143 Mondays vs 608 other overnights across the 751 trading‑day window, Welch t = 3.82 with p ≈ 0.00019 — only about a 2‑in‑10,000 chance the gap difference is pure luck. The shift shows up in the center of the distribution too (Monday median 2.58% vs midweek medians around 1.6–1.8%), so weekend risk raises both typical and tail overnight moves. Practical takeaway: treat the weekend as MARA’s largest overnight exposure — expect roughly 3% absolute moves into Monday opens versus ~2% on regular weeknights.
The fine print
- Analysis uses regular trading hours only (09:30–16:00 ET); pre-/after-hours moves are excluded.
- Tuesdays that follow market holidays (3–4 day closures) are counted as Tuesday and can dilute the Monday vs rest contrast.
- We analyzed absolute gaps only; this hides direction (downside vs upside).
- Results cover the most recent 36 months (751 trading days); crypto-volatility regime shifts could change weekend gap behavior.