NEW YORK (AFP) - The Dow and S&P 500 finished at record levels for the third straight session on Wednesday (Nov 23), but the Nasdaq dipped slightly as a post-election stock-buying rally showed signs of fatigue.

Financial stocks and industrials helped power the blue-chip index further above 19,000 as investors anticipate pro-growth policies from Washington following President-elect Donald Trump's election.

But technology giants such as Apple, Amazon, Microsoft and Google parent Alphabet all dropped.

Food shares were another weak point, with Mondelez International, Kraft Heinz and General Mills all losing about two percent.

The Dow Jones Industrial Average gained 0.3 per cent to 19,083.18.

The broad-based S&P 500 added 0.1 per cent at 2,204.72, while the tech-rich Nasdaq Composite Index lost 0.1 per cent at 5,380.68.

Analysts said trade volume was low ahead of the Thanksgiving holiday Thursday, when markets will be closed.

"It's pretty close to the flatline today," said Bill Lynch, director of investment at Hinsdale Associates. "Volume is real light as lots of people probably are taking their day off."

Drugmaker Eli Lilly sank 10.5 per cent after announcing the failure of a trial for a new drug to treat Alzheimer's Disease.

Juno Therapeutics, a small biopharmaceutical company, plunged 24.5 per cent after disclosing that it suspended a clinical trial for a leukaemia treatment after two patients suffered severe brain traumas, with one dying and the second not expected to recover.

Farm equipment manufacturer Deere surged 11 per cent as it reported better fourth-quarter earnings than analysts expected. Executives said the results reflected cost cuts.