XOM intraday high-low range on days with top-decile geopolitical news (Iran/Hormuz/sanctions)
The t-statistic is 3.85, and the p-value is 0.0002 — a gap that would appear by chance roughly twice in every ten thousand trials. Over 754 trading days, the 79 sessions with top-decile Iran, Hormuz, or sanctions coverage showed an average intraday swing of 7.0% of XOM's close, versus 4.7% on the other 675 days. The daily range itself carries information, even when the close direction does not.
That distinction is the core of this study: a supply-risk headline can leave XOM's close looking calm while the tape gets whipsawed all session. The analysis below measures the effect directly, using minute bars resampled to daily OHLC, daily article counts for the three geopolitical terms, and a Welch t-test comparing spike days to ordinary ones.
The full breakdown follows — the threshold used, the distribution of intraday volatility on both sets of days, and the caveats that come with a rough proxy that does not control for broader market stress.
On days with a top-decile spike in news articles mentioning Iran, Hormuz, or sanctions, does XOM's intraday high-low range expand significantly compared to typical days? Geopolitical flare-ups cause a surge in XOM's intraday volatility as supply-risk repricing unfolds, even if the daily close direction is ambiguous.
How this was measured
XOM minute bars resampled to daily OHLC; intraday volatility proxied as (high-low)/close. From XOM_news, articles mentioning 'Iran', 'Hormuz', or 'sanctions' were counted per calendar day. Threshold set at the 0.9 quantile of daily article counts across the sample; days with count ≥ threshold are labelled 'geopolitical spike days'. Distributions of intraday volatility on spike vs. non-spike days are compared with Welch's two-sample t-test (unequal variance).
The key numbers
Reading the numbers
On 79 geopolitical spike days, XOM's average intraday range was 7.00% versus 4.67% on typical days. That gap is very unlikely to be random (p≈0.0002), so the data support the idea that Iran/Hormuz/sanctions news spikes come with higher intraday volatility.
The charts
This box plot compares the full range of daily high-low spreads for the two groups. The geopolitical spike days have their whole distribution shifted upward, with an average of about 7% versus about 4.7% for typical days. Look at the boxes, not just the whiskers: most spike-day readings sit above the typical-day center. One curiosity is that the single widest day overall was actually a non-spike day at about 32%, but that outlier does not undo the general pattern that spike days are consistently wider.
The bar chart makes the same comparison in simpler form: the spike-day bar is roughly 7.0% and the typical-day bar is roughly 4.7%, so the spike-day average is about 50% higher. That is a meaningful jump for a single stock's daily range. For the user's question, this is the headline visual: when news about Iran, Hormuz, or sanctions hits a top-decile level, XOM's intraday volatility expands noticeably even though the closing direction can still go either way.
Intraday volatility summary
| Day type | N | Mean | Std | Median |
|---|---|---|---|---|
| Geopolitical spike | 79 | 0.07 | 0.0521 | 0.0508 |
| Non-spike | 675 | 0.0467 | 0.0405 | 0.0337 |
The takeaway
Yes — on top-decile Iran/Hormuz/sanctions news days, XOM's intraday high-low range expands, and the signal is real, not a coin flip. The average intraday swing on those 79 spike days was 7.0% of the close, versus 4.7% on the other 675 trading days, with medians of 5.1% and 3.4% respectively. The t-statistic is 3.85 with a p-value around 0.0002, meaning there's roughly a 2-in-10,000 chance you'd see this gap if the news had no genuine effect. So even when the close direction is ambiguous, the range itself widens meaningfully when supply-risk headlines spike. Practical takeaway: these news days behave like a distinct, elevated-volatility regime for XOM — worth accounting for in position sizing or hedging, though the effect is measured with a rough intraday proxy and without controlling for broader market stress.
The fine print
- The Iran/Hormuz/sanctions keyword filter is simplified; some relevant articles are missed and some irrelevant ones included.
- Intraday high-low range is a rough volatility proxy; high-frequency measures like Garman-Klass might tell a slightly different story.
- No control for broad market (SPX) volatility, so part of the gap could reflect market-wide stress coinciding with geopolitical news.
- The top-decile cutoff is data-driven and not tested out-of-sample, and the 79 spike days are a modest sample.