New concerns included rising oil prices, renewed inflation risks, climbing bond yields, and the possibility of a Federal Reserve rate hike next week.

Escalating tensions in the Middle East added to the uncertainty, while investors also digested a stronger-than-expected August jobs report.

1. US futures mixed amid rate-hike fears

US stock futures showed mixed performance early Tuesday as investors returned to the market following the Labor Day holiday on Monday.

Dow Jones futures fell 0.8% to 53,013 points, while S&P 500 futures declined 0.3% to 7,691.3 points. Nasdaq 100 futures remained virtually unchanged at 29,593 points.

Investors were returning to the market after a stronger-than-expected August jobs report fueled concerns that the US economy remains resilient enough to sustain high interest rates.

At the same time, rising oil prices and renewed tensions in the Middle East raised the risk of a new wave of inflation.

2. ADP data, Treasury auction, and bond sell-off in focus

Investors will get another look at the US labor market via the weekly ADP employment report, which uses a four-week moving average of private-sector employment to provide a more up-to-date picture of hiring conditions. The Treasury will also hold an auction for three-year bonds, and demand for the debt offering will provide insight into investor appetite for U.S. government bonds and their expectations regarding interest rates.

The auction takes place amidst pressure on global bond markets, which is driving up the cost of government borrowing. Bond prices and yields move in opposite directions: when investors sell bonds, yields rise.

U.S. national debt has now surpassed $40 trillion. The government regularly issues Treasury securities to fund expenditures and refinance existing debt. When investors demand higher yields to purchase this debt, the cost of government borrowing increases.

Rising Treasury yields affect more than just the government; they impact mortgage rates, corporate borrowing costs, and the rate investors use to value stocks. A sustained rise in yields can make stocks less attractive, particularly for companies whose valuations rely heavily on future growth.

3. Trump Targets Bombardier, Threatening U.S. Sales

On Monday, President Donald Trump called for an immediate halt to Bombardier’s sales in the United States, threatening to block the Canadian aircraft manufacturer’s access to a market that accounts for more than half of its revenue.

Bombardier, which trades in the U.S. under the ticker BDRAF, could suffer significant financial losses if this demand is carried out. The company is projected to generate approximately $10.2 billion in revenue in 2026, meaning its U.S. operations could represent around $5 billion in annual sales. Trump has previously used tariffs, trade restrictions, and threats against foreign companies as leverage in negotiations, making these latest comments particularly significant for investors even before any specific policy measures are announced.

If Bombardier suffers a significant loss of access to the US market, investors may need to revise their forecasts for the company's revenue and profits. More broadly, this episode highlights the ongoing risk that changes in US trade policy can rapidly impact companies with extensive international operations.

4. Iran threatens to establish a maritime exclusion zone in the Persian Gulf

Geopolitical tensions remained high after Iran threatened to respond to what it termed US "economic warfare" by imposing a maritime exclusion zone in the Persian Gulf.

Mohsen Rezaei, Secretary of Iran's Supreme National Security Council, stated that Iran had sent an unequivocal warning through recent missile strikes and that any further economic pressure would be met with the imposition of an exclusion zone covering the entire Gulf, extending to the perimeter of the US blockade.

He also noted that Iran's stance regarding US warships and military bases had undergone a "fundamental revision."

Meanwhile, attacks on Saudi Arabia by Iranian-backed Houthi forces have heightened concerns regarding the security of energy infrastructure and shipping routes in the region.

The Persian Gulf is critical to global energy supplies. Any disruption to shipping could drive up oil prices, fueling inflation and complicating...