The swing, one of the largest seen for quite some while, represented more than 200 points up and down on the index based on Fisher and Paykel's market capitalisation. Without the swing, the leading index would have been up more than 1 per cent as other stocks made good recoveries.
Jeremy Sullivan, investment adviser with Hamilton Hindin Greene, said Fisher and Paykel was stuck between "a combination of a stubborn NZ dollar and people seeing some light at the end of the Covid tunnel.
"Fisher and Paykel had a very good run-up in the pandemic, and hospitals will stockpile their products for future use. It is a good company but it's difficult see them reaching their earlier levels with more and more vaccines becoming available."
The New Zealand Government announced it has secured an extra 8.5m doses of Pfizer's vaccine by the middle of the year, to add to the 1.5m it has already bought – enough to vaccinate every New Zealander with two jabs.
Ebos Group recovered 89c or 3.15 per cent to $29.11; Synlait climbed 16c or 4.61 per cent to $3.63 after announcing an earnings downgrade last week; and travel software firm Serko rose 17c or 2.99 per cent to $5.86.
Mercury Energy, which is planning a $200m plus green bond offer at a fixed rate, rose 20c or 3.33 per cent to $6.20. Genesis increased 6c to $3.66, while Meridian fell 16c or 3.01 per cent to $5.15 and Contact was down 3c to $6.68.
Chorus was down 7.5c to $8.025; Freightways lost 19c or 1.74 per cent to $10.70; a2 Milk declined 21c or 2.07 per cent to $9.92; Auckland International Airport decreased 11c to $7.03; The Warehouse Group shed 8c or 2.41 per cent to $3.24; and Vital Healthcare fell 7c or 2.32 per cent to $2.95.
Retirement village operators Ryman Healthcare declined 12c to $15.10 and Summerset Group Holdings decreased 6c to $12.90 but Arvida rose 2c to $1.69.
My Food Bag's second day of trading ended with a 4c or 2.3 per cent fall to $1.70. Sullivan said their market debut was disappointing and it's now up to the company's management to deliver the results.
Other gainers were Scales Corporation, up 9c or 2.02 per cent to $4.55; Turners Automotive gaining 6c or 1.91 per cent to $3.20; Z Energy rising 7c or 2.57 per cent to $2.79; NZME increasing 3c or 3.61 per cent to 86c; and Evolve Education up 3c or 2.27 per cent to $1.35.
Earl Gasparich has stepped down as Oceania Healthcare chief executive and is moving to the top job at Metlifecare in place of Glen Sowry. Chief financial officer Brent Pattison will be the acting chief executive, and Oceania's share price was down 2c to $1.43.
Third Age Health Services announced a fully-imputed special dividend of 10.25 cents per share payable on March 29, and its share price gained 4c or 1.74 per cent to $2.34.