By Amara Osei

Oil spikes offered no systematic 20-session advantage for the S&P 500, although the index rose 7% during eight months of the Iran war. Brent gained 34% from February 27 to November 6, 2026, and the Nasdaq 100 added 8%.

Indicatr found the S&P 500 higher 20 sessions later in 12 of 16 spike cases, or 75%, against a 68% baseline across all days. Indicatr wrote: “Headlines move the day, not the trend.”

U.S. and Israeli strikes on Iran began the war on February 28, while the Strait of Hormuz remained closed or contested for most of the period. The study compared Brent, the S&P 500 and Nasdaq 100 from the February 27 pre-war close, using daily closes rather than intraday prices. It deliberately limited the analysis to market performance rather than political interpretation.

What did the four market phases show?

The eight-month analysis divides the period into four dated phases, from the initial shock through renewed escalation. Each comparison uses daily closing prices rather than intraday moves.

• Shock, February 27-March 30: Brent rose 49% in one month, while the S&P 500 fell 7.8% and the Nasdaq 100 fell 8.1%.
• Stocks looked through it, March 30-June 1: Both indices bottomed on March 30, with Brent at $109, six sessions before the April 8 ceasefire. Both reached record closes on April 15 while Brent remained 30% above its pre-war level; from March 30 to June 1, the S&P 500 gained 20% and the Nasdaq 100 gained 33%.
• Peace trade and relapse, June 1-August 31: A deal pushed Brent below its pre-war level to $71 on July 1, then collapsed in early July. Brent rose 42% to $101 by July 23; the S&P 500 gained 1% and the Nasdaq 100 lost 3% over the phase.
• Second escalation, September 1 onward: Brent closed at $117 on October 23, the war's highest close. The Federal Reserve raised rates on September 16, its first increase since 2023; the Nasdaq 100 then fell 15% from its October 6 high to November 5.

Across the full period, Brent's gain peaked at 60% on October 23, while the Nasdaq 100 and S&P 500 reached peaks of 25% and 14% on October 6. An AI-chip sell-off after the midterm elections, rather than the war, produced the S&P 500's largest single-session decline: 4.4% on November 5.

By autumn, inflation, interest rates and the AI-chip sell-off posed the main stock risks, rather than the oil price itself. Indicatr therefore advised readers to watch these second-round effects, not only the immediate oil move.

What did 16 oil spikes reveal?

Oil headlines moved stocks almost every day in both directions, yet barely altered the 20-session outcome. Brent closed at least 5% higher on 16 days. On 12 of those 16 sessions, the S&P 500 fell; on 16 sessions when Brent dropped at least 5%, the index rose 14 times.

Twenty sessions later, the S&P 500 stood higher in 12 of 16 cases, or 75%, compared with 68% for all days. A spike day therefore offered about as much timing value as any other day. Three of the four exceptions occurred during the war's first six sessions, on March 2, March 6 and March 9.

When did oil shocks lead to lasting stock gains?

On March 27, Brent jumped 6.2% to $106; on April 2, it jumped 9.0% to $109. Twenty sessions later, the S&P 500 stood 12.6% and 9.8% higher, respectively.

For the first three spikes, on March 2, March 6 and March 9, the S&P 500 stood 7.8%, 1.9% and 2.6% lower 20 sessions later. Indicatr wrote: “In the first days of a conflict nobody knows the worst case yet, and the selling went on for four weeks.” Those losses showed that buying the first spikes would have been early.

Did peace headlines provide a stronger signal?

The April 8 ceasefire did not produce sustained oil weakness: Brent rose 18% within four weeks. After the July 1 low, Brent rose 42% within three weeks. Peace headlines therefore proved no more reliable than war headlines for forecasting 20-session stock direction.

How much confidence belongs in the finding?

The analysis covered one conflict, eight months and 16 spike days, making it a case study rather than a statistical law. Its 20-day windows overlapped, and the spikes arrived in clusters. AI earnings, the Federal Reserve and the midterm elections also drove stocks.

The chart establishes what occurred at the same time, not what caused each move. The dataset comprised TradingView daily closes for TVC:UKOIL, the Brent contract for difference (CFD); SP:SPX; and NASDAQ:NDX, with event dates drawn from news reports.

The war remained ongoing, and the analysis represented its market status on November 9, 2026. Indicatr's next chart will apply the same format to the 2022 Russia-Ukraine shock and stocks after every major geopolitical shock since 1990.