Stock markets were torn Wednesday between optimism over artificial intelligence and a warning from US Federal Reserve chief Jerome Powell on interest rates.

Wall Street's main indices rose at the opening bell after finishing the previous day lower, but wobbled in morning trading.

Investors have enjoyed a months-long rally for equities that has pushed some markets to record highs, but the run-up took a pause Tuesday amid talk that the gains may have gone too far.

But Trade Nation analyst David Morrison characterised Tuesday's selloff as shallow.

"The general feeling is... that any pullback is a buying opportunity," he said.

A key driver of the rally has been expectations that the Fed will continue to cut US interest rates before the end of the year.

However, Powell cooled expectations

See Full Page