Concerns about the cost of artificial intelligence pushed stock markets lower Oct. 30 as investors questioned whether massive technology investments would deliver the returns they expected.

Financial results from Amazon and Intel added to the pressure after Google parent Alphabet’s sharp decline a day earlier. Chipmakers and companies supplying equipment for data centres also faced questions over spending and future profits.

At midday, the Nasdaq Composite was down about 2.6 per cent, while the S&P 500 fell 1.6 per cent and the Dow Jones Industrial Average slipped 0.7 per cent, according to MarketWatch.

Canadian stocks also weakened. Reuters reported the S&P/TSX Composite Index was down 1.57 per cent at 10:33 a.m. Eastern, with technology and mining shares contributing to the decline. Falling gold prices added to the losses.

The figures reflected trading during the day, rather than final closing results.

Amazon’s earnings illustrated the challenge facing companies investing heavily in AI: sales can grow while the cost of expansion consumes more cash than the business generates.

Amazon attributed the deterioration primarily to increased purchases of property and equipment for artificial intelligence.

Intel faced concerns about future earnings and weakness in the personal-computer market. Its shares fell roughly 28 per cent during trading, Reuters reported.

Intel management expected the personal-computer slowdown to continue through at least the first half of 2027, while describing demand for its server processors as strong.

The results suggest the market’s weakness reflects a combination of company-specific challenges and broader doubts about the pace and cost of AI expansion.

The declines were not shared equally across the stock market.

Charles Schwab reported that eight of the S&P 500’s 11 sectors rose Oct. 29, even as the overall index fell. An equal-weight version of the index, which gives each company the same influence, gained 1.2 per cent.

That difference illustrates how losses among a small number of large companies can pull a major stock index lower even when many other businesses are gaining.