XOM vs XLE 20-session drift after positive quarterly earnings surprises
The case for owning XOM into a beat is intuitive: a supermajor's earnings surprise should advertise margin control and cash-flow durability the sector basket hasn't priced. Over the past three years, the tape disagrees. Across eight positive quarterly surprises with a complete 20-session window, XOM averaged +1.16% while XLE averaged +2.52%, a mean shortfall of roughly 1.35 percentage points. XOM led the sector ETF in only three of those eight events.
That is a null result, not a proven reversal. Eight observations and a p-value of 0.149 leave ample room for luck, and the unconditional 20-session XOM-minus-XLE gap over the same stretch was mildly positive, which makes the post-surprise showing look worse rather than better.
The full event-by-event detail, the baseline comparison, and the statistical treatment are laid out below.
Over the past ~3 years, when XOM reports a positive quarterly earnings surprise, does XOM outperform XLE over the next 20 trading sessions? I expect a supermajor earnings beat to signal integrated margin control and cash-flow durability that the sector basket underreprices, so XOM should lead energy equities while the post-earnings drift plays out.
How this was measured
Resampled XOM and XLE minute bars to daily closing prices, aligned the two daily close series on common trading days, and isolated XOM quarterly earnings reports from the last ~3 years with a positive surprise. For each positive surprise, the first common trading day on or after the reported release date was used as the anchor, and forward returns were measured close-to-close over the following 20 trading sessions. The primary test is the pairwise excess return (XOM 20-session return minus XLE 20-session return), summarized by mean, median, fraction positive, and a one-sample t-test against zero. An unconditional overlapping 20-session XOM-minus-XLE baseline is also reported for context.
The key numbers
Reading the numbers
Across 8 positive XOM earnings surprises, XOM averaged +1.16% over the next 20 sessions while XLE averaged +2.52%, so XOM lagged by 1.35% on average and beat the sector ETF in only 38% of cases. The p=0.149 means the negative excess is not statistically robust.
The charts
The paired bars show each positive surprise date's next-20-session return for XOM and XLE. The eye should go to events like 2024-11-01, where XLE rose 7.45% versus XOM's 3.32%, and 2025-05-02, where XLE gained 1.19% while XOM fell 1.96%; XLE also led on 2026-07-31 by 4.32% to -0.18%. XOM's wins are fewer and mostly smaller, which lines up with the average XLE lead and argues against the idea that XOM reliably outperforms the sector basket after beats.
This scatter plots each event's XOM return on the horizontal axis against its XLE return on the vertical axis, so points above the diagonal mean XLE did better and points below it mean XOM did better. Most points sit above the diagonal — only 3 of 8 events had XOM ahead, matching the 38% hit rate — with the highest point on the vertical axis showing XLE's biggest 20-session gain at 7.45%, paired with a 3.32% XOM return. The cloud's center, with XOM averaging +1.16% and XLE averaging +2.52%, also sits above the equal-return line. That pattern says the sector basket, not XOM, generally captured more of the post-earnings drift in this window.
Event-level 20-session forward returns after positive XOM surprises
| report_date | surprise_value | XOM_20d | XLE_20d | XOM_minus_XLE |
|---|---|---|---|---|
| 2024-02-02 | 13.24 | 0.0323 | 0.0317 | 0.0006 |
| 2024-04-26 | 0.98 | -0.0306 | -0.0439 | 0.0133 |
| 2024-08-02 | 6.47 | 0.014 | 0.0303 | -0.0163 |
| 2024-11-01 | 2.13 | 0.0332 | 0.0745 | -0.0413 |
| 2025-01-31 | 10.97 | 0.0139 | -0.0005 | 0.0144 |
| 2025-05-02 | 1.15 | -0.0196 | 0.0119 | -0.0314 |
| 2025-08-01 | 5.13 | 0.0517 | 0.0544 | -0.0026 |
| 2026-07-31 | 11.68 | -0.0018 | 0.0432 | -0.045 |
The takeaway
No — the expected XOM-vs-XLE drift after a positive earnings surprise simply isn't there, and if anything the tape leans the other way. Across the 8 positive surprises with complete data, XOM averaged +1.16% over the following 20 sessions while XLE averaged +2.52%, leaving XOM behind by about 1.35 percentage points on average (median shortfall -0.94%). XOM beat the sector ETF in only 3 of the 8 events, or 38% of the time, so the typical outcome was losing ground, not gaining it. For context, the unconditional 20-session XOM-minus-XLE gap over the whole period was slightly positive (+0.19%), which makes the post-surprise result look worse, not better. With just 8 events and a p-value of 0.149, nothing here is statistically distinguishable from noise — that's roughly a 15-in-100 chance of seeing a gap this size from luck alone, so this is not a proven underperformance signal either. Bottom line: the thesis that a supermajor beat signals margin control the sector basket underprices doesn't show up in the price action — this is a null result with a mild negative tilt, and the sample is too thin to lean on in either direction.
The fine print
- Only 8 positive-surprise events in ~3 years — this is an anecdote count, not a sample you can draw a statistical conclusion from.
- XLE holds XOM as a top constituent, so the benchmark is partly the thing being tested; a sector-ex-XOM comparison would likely show bigger relative moves.
- Release times aren't distinguished, so before-open and after-close reports are anchored the same way — returns start at the first common day's close, which can blur the reaction window.
- The +0.19% unconditional baseline uses overlapping 20-session windows, so it's context rather than an independent control.