Regional markets clawed back Wednesday's losses yesterday after the United States Federal Reserve soothed investor nerves with assurance that interest rates would remain lower for longer.

The Straits Times Index (STI) has gone only one way this week: up. It rose 48.96 points or 1.67 per cent to 2,973.54 yesterday, with gainers outnumbering losers 329 to 184 on trade of 2.23 billion shares worth $1.96 billion.

It was the same elsewhere. The Hang Seng gained 1.2 per cent following Wednesday's sell-off after Hong Kong announced that stamp duties on stock transactions would rise for the first time in decades.

Japan's Nikkei 225 added 1.67 per cent, the Shanghai Composite rose 0.59 per cent and Malaysia's KLCI advanced 1.54 per cent.

"China markets have quickly forgiven the Hong Kong stamp duty rise," said Mr Jeffrey Halley, senior market analyst, Asia-Pacific, at Oanda.

"Today's price action emphasises just how much capital remains on the sidelines, ready to be deployed on any material market dips."

There was a notable rally by Singapore Airlines here, which jumped 7.25 per cent to $5.03 amid a global airline rebound after US regulators found that Johnson & Johnson's Covid-19 vaccine was safe and effective.

Qantas helped the mood by stating that it aims to restart international travel in October.

Sembcorp Industries climbed 6.02 per cent to $1.76 after analysts affirmed their "buy" calls on the stock for its environmental, social and governance agenda, while UOB rose 3.22 per cent to $24.65, despite reporting a 32 per cent drop in fourth-quarter net profit.

The most active counter was Thomson Medical, which gained 9.17 per cent to 11.9 cents - a two-year high - on a volume of 238.7 million shares traded. Its shares have more than doubled since Feb 8 when it announced a reversal into the black for its first half.