The latest National Federation of Independent Business survey drew attention from analysts at Bespoke Investment Group, whose review of the data found a growing share of small business owners citing weak sales as their foremost concern. The asset manager noted that, of all the options presented in the survey, a top ranking for poor sales stands out as the most unwelcome outcome, adding that previous periods of economic contraction have consistently shown that particular reading climbing at a noticeable pace.

The NFIB index retreated to 97.9 in September from 98.7 the month before, and analysts Samuel Tombs and Oliver Allen at Pantheon Macroeconomics noted that broader business surveys pointed to a modest easing of activity toward the close of the third quarter, a trend they attributed in part to a rebound in global energy prices. Participation in the survey has thinned considerably, with just 411 companies submitting responses compared with roughly 1,200 that did so a decade earlier.

Moody's Analytics economist Mark Zandi described the U.S. economy as being in a position of exposure to downside risk, pointing in particular to labor market data showing that monthly payroll additions have averaged roughly 40,000 over the past year — a figure that falls to near zero once healthcare-sector hiring is set aside. In a recent interview, he noted that new hiring activity had stalled, average hours on the job remained depressed, and that the headline unemployment figure — though still low — partly reflected a shrinking pool of active job-seekers, driven by a wave of retirements and a slowdown in immigration rather than by stronger employment conditions.

Zandi also expressed concern that elevated borrowing costs — driven by both the Federal Reserve and bond markets — could weigh on capital expenditure tied to artificial intelligence, noting that a higher cost of capital makes such investment more expensive while declining valuations restrict access to the funding needed to maintain the current pace of AI infrastructure development. He added that if rates remain at those levels or above for more than a quarter or two, the AI sector could be among the first parts of the economy to feel the strain — a concern that comes as the consumer price index for September registered at 3.7%, up from 3.4% the previous month and above analyst forecasts.

The Federal Reserve may face pressure to push interest rates higher, while Harris Financial Group analyst Jamie Cox told a news outlet that price pressures remain elevated and that relief is unlikely until two ongoing armed conflicts reach resolution. Pimco's Tiffany Wilding noted that the data release put the Federal Reserve in a difficult position, given that committee members had been indicating a rate hold later in the month, while a separate analyst drew a parallel to the central bank's earlier characterisation of Covid-era inflation as temporary — arguing that policymakers now faced a comparable analytical misjudgement in their reading of the energy supply shock.

Following the release of the inflation data, futures markets placed roughly even odds on the central bank lifting borrowing costs again in October, while equity traders moved away from technology holdings over the preceding day, pushing sell-offs across global markets. South Korea's KOSPI index dropped 8 percent on the session, with the selloff deep enough at one point to activate an automatic trading suspension.

Pre-session trading in Nasdaq futures slipped 1.03%. Shares in CoreWeave shed 15.46% across the regular session before giving up a further 5.89% in after-hours activity, while Oracle's stock retreated 8.83% during the trading day and then slipped an additional 1.57% once markets had closed. Chipmakers traded uniformly in the red, with no corner of the sector holding ground.

The sell-off unfolded even as TSMC posted third-quarter results that cleared analyst forecasts and announced plans to lift capital expenditure over the following two years. At the close of trading, Apple's stock settled at a record high, lifting the company's overall valuation above the $5 trillion mark — a level that only Nvidia had reached before it. Anthropic disclosed that its finances had reached adjusted profitability, even as third-quarter revenue of $17 billion came in below what earlier forecasts had projected.

Bond traders found themselves divided over a fundamental question about the 10-year U.S. Treasury note — whether it still acted as a safe-haven asset or had taken on the character of a risk-carrying instrument — a tension that pulled the market into the wider instability spreading across financial assets. At 5.32%, the bond's yield reached its session high before retreating to 5.08% — a range that stands out for an instrument typically associated with measured, gradual movement.

Futures tied to the S&P 500 index slipped by a quarter of a percent, and the index closed lower by 1.11 percent on the day. At the open, the Stoxx 600 shed around a tenth of a percent, whereas London's FTSE 100 had edged into positive territory — up close to half a percent — by the midday mark.

South Korea's KOSPI index posted a decline of 7.57 percent during the Asian trading session. The Nikkei 225 index in Tokyo shed roughly 4.90 percent of its value. The Nifty 50 index in India posted a gain of 1.68 percent on the session, while the CSI 300 index in China shed 1.23% of its value during the session.

Brent crude held at $106 a barrel. Trading in Bitcoin pushed the cryptocurrency's price down to the $81,265 mark.