The S&P/NZX 50 Index rose 90.42 points, or 0.7%, to 12,856.87, with turnover across the wider market a respectable $252.8 million.

Investors started the week nervous about the spread of the omicron variant of covid-19, with some nations imposing restrictions to rein in the virus. Meanwhile, US president Joe Biden’s major infrastructure spending programme hit a snag as it lost support in the Senate.

That’s kept traders wary of risk-sensitive currencies such as the NZ dollar, which fell across most major currencies today, trading at 67.12 US cents at 3pm in Wellington, down from 67.34 cents yesterday. The trade-weighted index was at 72.32, down from 72.50.

“The sentiment indicating three amigos, the Canadian, Australian and NZ dollars, did not rally on US dollar weakness overnight elsewhere. That suggests that markets remain vulnerable to more virus headlines and that dips in the US dollar may be shallow,” said Jeffrey Halley, senior market analyst Asia Pacific at Oanda.

The weaker dollar bolstered the earnings outlook for exporters, with high-tech components maker Rakon the best performer on the wider market, rising 7.2% to $1.93 and extending this year’s gain to almost 233%.

Grant Williamson, a director at Hamilton Hindin Greene, said Rakon had come into its own with the advent of 5G technologies, bouncing back from losing its market leading position in the late 2000s.

Utilities software developer Gentrack gained 5.6% to $1.90, while church management software developer Pushpay climbed 4.1% to $1.28, and cancer diagnostic firm Pacific Edge advanced 3.9% to $1.35.

Fisher & Paykel Healthcare extended its gain, up 2.5% at $32.99, with the double tailwind of a weaker dollar and potential demand for its products in an omicron outbreak.

“They’re certainly having a very good day, but are really still stuck in a trading range,” Williamson said.

NZ’s government today delayed its phased re-opening of the borders in response to the omicron outbreak.

Air New Zealand rose 1.3% to $1.51. The national carrier said it will cancel about 120 international flights because of the delay.

Auckland International Airport increased 0.3% to $7.61, while Tourism Holdings fell 1% to $3.04 and SkyCity Entertainment Group declined 0.7% to $2.99.

Sanford posted the day’s biggest decline on the top 50 index, falling 2.1% to $4.78.