S&P 500 rose 2% in Q3 2026, but oil and bond yields drove caution

In short: The S&P 500 gained about 2% in the third quarter of 2026, but the move hid growing investor caution tied to oil prices, bond yields, and AI profit expectations.

What's going on

The S&P 500, a widely followed index of large US companies, rose roughly 2% in the third quarter of 2026. That sounds calm, but the market’s gains were not evenly spread.

Energy stocks did much of the lifting. The New York Times reported the energy sector rose about 16.5%, helped by higher oil and gas prices after renewed US and Iran hostilities. Reuters reported oil rose about 40% during the quarter. Higher energy prices can act like a tax on everyday life, since they can push up the cost of shipping, heating, and many goods, and that can keep inflation worries alive.

At the same time, higher bond yields weighed on many other stocks. Reuters reported the 10-year US Treasury yield moved above 5%, the highest since before the 2007 financial crisis. A bond yield is the return you get for lending money to the government (like interest on a savings account). When that return rises, bonds can look more attractive than stocks, and it also raises borrowing costs for companies and households.

Investors also appeared to be more selective about AI-related stocks. The Times described a more cautious mood about whether fast profit growth linked to AI can keep going, especially when stock prices already assume very strong results.

What to watch

If oil stays high and bond yields stay elevated, investors may keep favoring some sectors over others, and they may keep questioning whether big AI profit forecasts will hold up.

Source: NYTimes