The Donald Trump Effect: Oil Higher, Stocks Down, as War with Iran Escalates
Author: Kathleen Brooks, Research Director UK
Date: 13 July 2026
Overview
As tensions between the US and Iran escalate, President Donald Trump has announced the reinstatement of a naval blockade in the Strait of Hormuz, imposing a 20% fee on all cargo passing through. This decision, justified by Trump as a matter of 'fairness', is expected to have immediate effects on global markets.
Market Reactions
The announcement has led to a significant increase in oil prices, with Brent crude rising nearly 6% to trade above $80 per barrel. Conversely, US stock markets are experiencing declines, particularly in the technology sector, with notable drops in companies like SanDisk (down 11%) and Marvell Technology and Arm Holdings (both down 7%).
Government bond yields have also reacted, with UK 10-year yields increasing by 10 basis points, nearing 5%, while US 10-year Treasury yields rose by 5 basis points, currently at 4.61%. French 10-year yields saw a more substantial increase of 15 basis points.
Interest Rate Expectations
The surge in oil prices has prompted a recalibration of interest rate hike expectations, with the probability of a Federal Reserve rate hike at the upcoming FOMC meeting rising from 20% to 40%. Higher oil prices are raising inflation concerns, prompting the Bank of England (BOE) and the European Central Bank (ECB) to monitor potential inflationary effects closely.
Fed Governor Chris Waller has indicated that a rate hike should be considered if the upcoming Consumer Price Index (CPI) report exceeds expectations, suggesting a readiness among Fed members to act on inflation concerns.
Gold and Stock Market Trends
Gold prices are also under pressure, falling 2.5% to test the $4000 per ounce level. The combination of rising yields and expectations of Fed rate hikes is creating a bearish environment for gold, especially in light of escalating geopolitical tensions.
The stock market, particularly the Nasdaq, is showing weakness, with its performance increasingly tied to oil prices and Treasury yields. A continuation of the blockade in the Strait of Hormuz could push Treasury yields closer to 5%, potentially leading to further declines in stock prices and gold.
Future Outlook
Market sentiment is heavily influenced by Trump's actions. If he retracts the blockade threat, there could be a swift recovery in both stock and gold markets. However, if the blockade remains in place, oil prices could rise towards $100 per barrel, exacerbating current market pressures.