A strong rebound by financials helped Wall Street's main indexes close firmly positive on Thursday, after some of the country's largest lenders came to the rescue of embattled First Republic Bank.

The technology sector also contributed to the gains, helping to boost the Nasdaq Composite to its strongest performance since February 2, 2022.

The latest twist in the US regional banks saga came on the heels of a 50 basis point rate hike by the European Central Bank, which earlier in the day had dampened investor sentiment already hurt by fears of a banking crisis.

Financial institutions, including JP Morgan Chase and Morgan Stanley, confirmed earlier reports they would deposit up to US$30 billion into First Republic Bank's coffers to stabilise the lender.

"Banks are looking out for one another," said Huntington Private Bank chief investment officer, John Augustine.

"We had two outliers go down and now they want to save what is considered a more mainstream bank."

The financial lifeline buoyed First Republic Bank, which gained 9.98 percent.

Concerns about banks have rattled the stock market in recent days after the collapse of SVB Financial fueled contagion fears.

Meanwhile, US Treasury Secretary Janet Yellen said the US banking system remains sound and Americans can feel confident that their deposits will be there when needed.

US-listed shares of Credit Suisse advanced after the bank secured a credit line of up to US$54 billion from the Swiss National Bank to shore up liquidity and investor confidence.

The Dow Jones Industrial Average rose 1.2 percent to 32,246, the S&P 500 gained 1.8 percent to 3,960 and the Nasdaq Composite added 2.5 percent to 11,717.

Data showed the number of Americans filing new claims for unemployment benefits fell more than expected last week, pointing to continued labour market strength, which could persuade the Fed to keep raising rates further.

Weak retail sales figures, as well as data showing a downward trend in producer inflation, on Wednesday had bolstered bets of a small rate hike by the Federal Reserve at its meet concluding on March 22.

Money markets are still largely pricing in a 25-basis-point rate hike by the Fed at its March 22 policy announcement. .

Facebook parent Meta Platforms and Snapchat operator Snap climbed 3.63 percent and 7.25 percent after the US administration threatened to impose a ban on rival TikTok. (Reuters)