Wall St up after tech sell-off as yields retreat

The main US stock indexes have recovered after a technology-driven slump in the previous session as government bond yields retreated from multi-decade highs and investors assessed a slew of corporate updates.

Vaccine-maker Moderna's shares more than doubled after its personalised mRNA cancer therapy developed with Merck cut the risk of melanoma recurrence and spread in a late-stage trial.

Biotech peers also gained: Novavax was up 6.8 per cent while US-listed shares of BioNTech rallied 17.5 per cent.

The S&P 500 healthcare sector rose 2.7 per cent to hit a record high and was the biggest gainer on the benchmark index.

Marvell Technologies surged about 9.0 per cent after the chipmaker issued Alphabet's Google a warrant to buy a stake worth about $US12.18 billion ($A17.22 billion).

Broadcom declined more than 4.0 per cent after the deal, weighing on the Philadelphia SE Semiconductor index 0.7 per cent.

Tech stocks on the benchmark S&P 500 declined 0.4 per cent, limiting market gains.

Heavyweight tech stocks came under sharp selling pressure on Tuesday as government yields hit multi-decade highs on concerns over ballooning government debt and geopolitics that battered the bond market.

The yield on the 30-year Treasury bond retreated from its highest level since 2007 after the US Treasury announced it would double the size of liquidity support buyback operations for longer-dated bonds, boosting risk appetite. It was last at 5.209 per cent.

"Most tech companies are priced mainly on forward earnings expectations and when interest rates creep up, those expectations are worth less and the stocks are worth less," said Robert Pavlik, senior portfolio manager at Dakota Wealth.

In early trading on Wednesday, the Dow Jones Industrial Average rose 119.94 points, or 0.22 per cent, to 53,463.34, the S&P 500 gained 28.48 points, or 0.37 per cent, to 7,720.24 and the Nasdaq Composite was up 67.17 points, or 0.26 per cent, to 26,356.89.

Investors also scrutinised quarterly earnings from retailers for insight into the health of the US consumer.

Target was up 3.3 per cent after raising its annual sales forecast, while Lowe's gained 1.8 per cent despite trimming its annual sales growth forecast.

Estee Lauder jumped more than 14 per cent after the cosmetics maker forecast annual profit above Wall Street estimates.