Thursday, August 27, 2026 Closing bell

Nvidia carries the index, average stock slips

What happened

The S&P 500 closed up 0.72% at 7,730.73 and the Nasdaq Composite jumped 1.57% to 26,540.78, while the Dow Jones Industrial Average managed only 0.19% to 53,564.21. Nvidia rose about 8% to $227.06 and added roughly $435 billion of market value in a single session, more than most companies in the index are worth in total. Underneath those green numbers the day was much narrower than it looks, because technology was the only sector meaningfully higher while financials, healthcare and utilities all fell.

Why it happened

Nvidia reported quarterly revenue of $96.2 billion and guided to about $108 billion for the current quarter, a forecast that assumes no sales to China at all. That mattered less as a number than as an answer to the question hanging over the market all summer, which is whether companies will keep spending enormous sums on artificial intelligence hardware or whether that spending is about to slow. The guidance said the spending continues, so investors bought not just Nvidia but the software companies that sell AI products, which is why Salesforce rose about 22% and CrowdStrike about 18% on their own earnings the same day.

Here is the part worth slowing down on. The S&P 500 is capitalization weighted, meaning each company counts in proportion to its total market value rather than counting equally, so the largest company in the index moves the index hundreds of times more than the smallest one does. Nvidia is large enough that an 8% move in one stock can lift the whole index even on a day when more companies fall than rise. The equal weight version of the index, which counts every company the same regardless of size, was slightly negative through the afternoon.

Working against the market was the inflation report released Wednesday. The personal consumption expenditures price index, the inflation measure the Federal Reserve actually targets, came in at 3.7% over the past year, and the core version that strips out food and energy came in at 3.3%. Both are well above the Fed's 2% goal and neither improved from June. That pushed the yield on the 10 year Treasury note, which is the interest rate the US government pays to borrow for a decade, up to about 4.68%, and it left traders pricing roughly a 45% chance that the Fed raises rates by December rather than cutting them. Higher borrowing costs are exactly what utilities, real estate and banks do not want, which is why they lagged while Nvidia soared.

What it means for you

If you are watching mortgage rates, today was mildly bad news. Fixed mortgage rates track the 10 year Treasury yield rather than the Fed's policy rate, and that yield rose again on the inflation report, so the case for waiting out a rate drop got weaker rather than stronger. Three Fed officials already voted for a rate increase in July, and the market now sees a hike as nearly as likely as no change at all by year end.

On the other side, high rates keep paying you on cash. Savings accounts and money market funds still yield well, and if inflation stays near 3.7% while your savings earn more than that, you are quietly ahead. That is not permanent, so it is worth checking what your bank actually pays rather than assuming.

For your retirement accounts, the honest answer is that today was good and slightly uncomfortable at the same time. Your index fund went up, but it went up because of a handful of enormous technology companies rather than because the economy broadly improved. That concentration works beautifully until it does not. This is not a reason to sell anything, it is a reason to know what you actually own, because a US total market fund today is far more of a bet on a few AI companies than it was five years ago.

On groceries and everyday costs, nothing changed today, but the inflation reading is the pattern to notice. Prices are still rising about 3.7% a year, which is slower than the 2022 spike but faster than the roughly 2% pace that made the 2010s feel stable. If your raise this year was under 3.7%, you took a real pay cut in purchasing power even though the number on your paycheck went up.

What to watch tomorrow

Fed Chair Kevin Warsh delivers his first Jackson Hole speech Friday morning. Jackson Hole is an annual conference of central bankers in Wyoming where Fed chairs have historically signaled shifts in policy thinking. Economists expect him to avoid committing to any specific rate decision and instead lay out how he thinks about inflation, which given today's yield move is the thing bond markets will react to first.