US stock futures are set for a negative start on April 20, with declines between 0.4% and 0.5% across major indices, including the Dow Jones Industrial Average, S&P 500, and Nasdaq. This downturn follows heightened tensions in the Middle East after the US Navy's seizure of an Iranian vessel in the Strait of Hormuz, which Iran condemned as piracy. The situation has raised concerns about oil transport, contributing to a surge in Brent crude prices, which rose 8% to $97.50 per barrel. Last week, both the S&P 500 and Nasdaq reached record highs, buoyed by optimism regarding a potential ceasefire and the reopening of the Strait. However, with the ceasefire set to expire soon and Iran's reluctance to engage in talks, market sentiment has shifted. Additionally, traders are closely watching Kevin Warsh's Senate confirmation hearing for the Federal Reserve Chair position, which could further influence market dynamics. Despite the overall risk-off mood, certain sectors, particularly those linked to AI, are showing resilience, with companies like Marvell Technology gaining traction.