US and Iran pause military strikes over Strait of Hormuz tensions; oil prices fall 5%
Measured from 27 Jul 2026 (event start), not the 27 Jul 2026 announcement
Defense contractors moved +8.3%, the largest reaction measured, though not statistically significant, meaning it may reflect normal market noise rather than the event itself. This is a provisional result; the full measurement window is not yet complete.
LMT, RTX, NOC · up
What Happened
After approximately two weeks of tit-for-tat bombing campaigns, the United States paused its air campaign against Iran over the weekend of July 26-27, 2026. Iran responded by suspending its retaliatory strikes, creating a de-escalation window around the Strait of Hormuz. The pause represents a significant shift from the February 2026 escalation that had driven crude prices toward $100 per barrel and created acute supply uncertainty. Brent crude had surged 27 percent over two weeks to $96.78 before this pause, with prices briefly exceeding $100. The immediate consequence is a sharp reversal in oil prices: WTI fell 5 percent on Monday as traders priced out war-risk premiums. Iran and Oman are now holding talks on Hormuz security, suggesting diplomatic channels are reopening.
First meaningful de-escalation of Iran conflict since February 2026; reverses 27% crude rally and removes immediate supply-disruption risk to global refined products.
Pause effective July 26-27, 2026; uncertainty whether it will hold remains material risk factor for forward guidance.
Reporting confirms US refrained from striking Iran for second consecutive night as of July 27, 2026. Iran reportedly signaled it would suspend retaliatory attacks if US pause holds. Timeline is current and verified.
Read how dates work →Partial reaction shown. Significance flags are marked provisional and may change as more price data accumulates.
How To Read This
Each sector below is a basket of named stocks. The percentage shown is the move beyond the overall market (S&P 500) , what event studies call the . A move only counts as when it sits clearly outside that basket's normal weekly swings.
How Much Sectors Moved
Path over time. Click a sector in the legend to toggle it. Dashed lines mark key moments.
Defense contractors moved most at +8.3% against the market, the direction you would expect from a bombing. None of the moves cleared the significance threshold. Read the direction as flavour, not signal.
Volatility
Volatility measures how erratic prices became, a separate signal from the direction of the move.
Market fear rose modestly
- Oil tanker operators44% → 26%1.7x calmer after
- Oil & gas producers24% → 27%1.2x more volatile after
- Defense contractors33% → 16%2.0x calmer after
- Gold21% → 28%1.3x more volatile after
- Airline stocks33% → 45%1.4x more volatile after
The VIX rose 2.0 percent across the window, essentially flat. Read this as the market's demand for protection, not the direction of any single sector.
A ratio above 1.00 means the sector's daily-price swings widened after the event. Airline stocks became the most erratic at 1.36×, and 3 of 5 sectors traded meaningfully wider than they did before. Volatility is a separate signal from direction: a sector can end flat and still have traded wildly along the way.
Phases
| Sector | Peak Move | Peak Day | Reverted By |
|---|---|---|---|
| Oil tanker operators | +8.1% | Day 2 | Day 6 |
| Oil & gas producers | +5.8% | Day 2 | Day 5 |
| Defense contractors | +10.9% | Day 0 | Still elevated |
| Gold | +2.7% | Day 2 | Day 4 |
| Airline stocks | +8.5% | Day 7 | Still elevated |
The reaction peaked around day 3 on average. 3 of 5 sectors reverted inside the window, 2 were still elevated at the close. A reaction that reverts is a shock priced in; one that stays is a re-rating.
Historical Precedents
Companies Most Affected
Measured 10 days after the event. Reaction still developing; the full window is not yet complete.
This tool informs your decision. It does not give investment advice.