NEW YORK (AFP) - Wall Street stocks ended higher on Thursday (June 8) as investors took in stride dramatic testimony from ousted FBI chief James Comey on his firing by President Donald Trump and links to the Russia investigation.

The advance was good enough to lift the Nasdaq to a fresh record, while the Dow and S&P 500 eked out modest gains.

Comey, who Trump fired last month amid an investigation into the presidential campaign's connections with Russia, testified that Trump asked him for "loyalty" and to drop a criminal investigation into former National Security Adviser Mike Flynn.

Comey said he took painstaking notes of the extraordinary encounters for fear Trump might "lie" about the meetings, a step he did not deem necessary with earlier presidents.

While the testimony painted an unflattering picture of Trump, analysts said most of the information had been aired in press reports and the disclosures themselves were not disturbing enough to end the market's bullish sentiment.

Comey himself declined to address whether Trump's conduct constituted obstruction of justice, an impeachable offence.

"Based on what the stock market is doing, it did not see a smoking gun based on this testimony from Mr Comey," said Briefing.com Patrick O'Hare.

The Nasdaq Composite Index gained 0.4 per cent to close the session at 6,321.76, eclipsing a record set last Friday.

The Dow Jones Industrial Average added less than 0.1 per cent to finish at 21,182.53, while the broad-based S&P 500 rose a hair to 2,433.79.

Banking shares were strong, with Bank of America, Citigroup and JPMorgan Chase all winning more than 1 per cent.

Media shares were pressured, with CBS, Comcast and Disney all down at least 1 per cent.

Yahoo shares jumped 10.2 per cent as shareholders endorsed the US$4.5 billion (S$6.2 billion) sale of the tech giant's core business to Verizon. Verizon lost 0.7 per cent.

Nordstrom surged 10.3 per cent as it announced it was weighing the possibility of taking the company private.