A range of index changes saw some big swings in individual stocks but overall the market finished in slightly positive territory.
The S&P/NZX50 closed up 10.73 points or 0.09 per cent up on 12,551.93 points.
Turnover was 85.5 million shares worth $419 million.
Harbour Asset Management portfolio manager Shane Solly said index changes in both the FTSE indices and the NZX portfolio indices had influenced market movements.
And globally longer maturity government bond yields fell because of the view the market had got ahead of itself over fears about rising inflation.
Solly said that had pushed investors back into growth stocks again.
"During the day we have seen some big moves but if you look at the market on its own it's not up by much."
Shares in A2 Milk gained the most rising 6.3 per cent or 40c to $6.75 followed by Synlait Milk which rose 20c or 5.54 per cent to $3.81.
Solly said around 6.3 million shares in A2 had changed hands.
"That is quite a big number. Bigger than a normal day's trading in the stock."
Normally it only traded a couple of million shares.
Digital church donation service provider Pushpay Holdings also saw a substantial gain in its shares rising 7c or 4 per cent to $1.82.
While Tourism Holdings also rose 9c or 3.67 per cent to $2.54.
Ryman Healthcare rose 1.93 per cent or 25c to $13.23 which was also likely to be due to index changes while rival retirement village operator Oceania Healthcare shares fell 4 per cent or 6c to $1.44.
Shares in Air New Zealand dipped 0.31 per cent or half a cent to $1.615 after giving an update on its profit guidance which was slightly lower than the market expected.
Air New Zealand said it expected losses before other significant items and taxation "will not exceed" $450m for the 2021 financial year.
Solly said the airline had worked hard to get to a break-even point with its cash burn.
The airline said it was not expecting any meaningful recovery in long-haul demand in the 2022 financial year, notwithstanding global vaccination programmes and the potential for long-haul borders to begin reopening progressively in the second half of the financial year.
Guidance for its FY22 was lower than the market had expected with the company highlighting there were a number government support measures that would not be continuing.
The airline still has a potential capital raise on its horizon before the end of September.
Precinct Properties also saw its shares dip 8c or 4.79 per cent to $1.59 after it announced a $250m capital raising to fund the acquisition of two Wellington office buildings.
Solly said government tenants were seen as highly desirable so there was good demand for that type of asset but it could take a few days for the market to digest the capital raise.
Shares in online lender Harmoney fell 9c or 6 per cent to $1.41 while Freightways was also down 50c or 3.98 per cent to $12.05.