Shares in Fisher and Paykel Healthcare plunged in value by more than 10 per cent, despite the respiratory products maker announcing an 82 per cent lift in its annual net profit to $524 million.
By mid afternoon the stock was at $28.79, down $2.59 from Wednesday's close, but off its session low of $27.81.
In its result, the company said its operating revenue shot up by 56 per cent to $1.97 billion based on Covid-19 driven demand.
The company did not give an earnings guidance for the current year.
"The result itself a little below most forecasts, although this was always going to be an unusual year due to Covid-19," Matt Goodson, managing director of Salt Funds, said.
"The issue is more the outlook and the earnings path over the next year or two as the benefits from Covid-19 hospitalisations fade, but it takes time for clinical practice to adapt and use up surplus installed capacity," he said.
"We may see downgrades to next year or two's forecasts before solid growth resumes in the medium term," he said.
Adrian Allbon, Jarden director, equity research, said the result was soft, relative to very high expectations built up in the market.
"We suspect the reported miss and lack of clear guidance is likely to weigh on the stock," Allbon said.
F&P Healthcare managing director and chief executive Lewis Gradon said it had been an extraordinary year with healthcare professionals around the world operating often in difficult conditions.
The record result was driven by the company's hospital product group, which includes "Optiflow" and "Airvo" systems used to deliver nasal high airflow therapy.
Sales of its hospital hardware and consumables have continued to track Covid-19 hospitalisation surges in countries around the world, he said.
The company is the NZX's biggest by market capitalisation.
F&P Healthcare approved a final dividend of 22.0 cents per share, an increase of 42 per cent on the final dividend last year, bringing the total dividend for the year to 38.0 cents per share, an increase of 38 per cent.
While no guidance was provided, the company said a global vaccine rollout during 2022 was likely to reduce global hospitalisations requiring respiratory support for Covid-19 compared to 2021.
"It has been an extraordinary year and we want to thank healthcare professionals for giving their all to care for patients, often under the most difficult conditions," Gradon said in a statement.
"We also want to acknowledge the people of F&P Healthcare for their commitment to delivering for our customers, and the partners and families of our employees for the invaluable contribution they have made," he said.
In recognition of the "incredible contributions" of its staff, the board approved a profit-sharing bonus totalling $29m for the 2021 financial year.
Revenue for the hospital product group was $1.5b, an increase of 87 per cent over the previous financial year, or 94 per cent in constant currency terms.
Hospital products made up 76 per cent of the company's operating revenue.
Although Covid-19 restrictions impacted sleep clinics and reduced OSA (obstructive sleep apnea) diagnosis rates, revenue for the homecare product group was $466m, an increase of 2 per cent over the previous year, or 4 per cent in constant currency terms.
F&P Healthcare's gross margin decreased by 295 basis points for the year to 63 per cent.
This included increased freight costs and high airfreight utilisation, which adversely impacted constant currency gross margin by about 230 basis points.
Freight and additional Covid-19 related costs were offset by overhead leverage due to volume increases outpacing cost growth during the year.
F&P Healthcare committed $20m to establish the Fisher & Paykel Healthcare Foundation during the 2021 financial year.
The foundation's charitable purposes include supporting and funding health research and programmes that improve access to healthcare.