Crude oil jumped more than 5% on May 4 after reports that a tanker was struck in the Strait of Hormuz, pushing Brent crude past $114 a barrel as traders priced in a sharp rise in supply-chain risk through one of the world's most critical shipping lanes.

The Strait of Hormuz is the narrow waterway between Iran and Oman through which roughly 20% of global oil supply passes every day. Any threat to traffic there moves oil markets fast, and this incident did exactly that.

What Triggered the Move

The tanker strike came as tensions between the United States and Iran escalated sharply. President Trump said the U.S. would guide ships safely through the strait. Iran responded by warning of military action against U.S. forces and called on vessels to coordinate passage with Iranian authorities before entering the waterway. That direct clash of authority over a shared chokepoint is what sent prices spiking.

The mechanism here is straightforward. When two powers contest control of the same shipping lane, insurers raise war-risk premiums, shipping companies reroute or delay, and oil traders add a risk premium to every barrel that needs to move through that corridor. Higher insurance costs and potential delays translate directly into tighter effective supply, even if no oil fields are shut down.

What This Means for Markets

A sustained price above $114 a barrel raises costs across the board. Fuel, plastics, fertilizers, and freight all get more expensive when crude stays elevated. For India, which imports roughly 85% of its oil needs, a multi-dollar spike in Brent adds to the import bill, pressures the rupee, and can feed into retail fuel prices if sustained.

The immediate question for traders is whether the tanker strike was a one-off incident or the start of a broader pattern of interference in Hormuz traffic. If U.S. and Iranian naval forces come into closer contact, each incident risks another leg up in prices.

Watch for any formal response from Iran's navy, changes in U.S. naval deployments in the Gulf, and whether major tanker operators begin rerouting around the strait. Those signals will determine whether the 5% spike holds or fades as a short-term shock.