"IPOs have been a bit fragile and if [the share price] is up at the end of the day that would be a great result for Metro," he said.
However, Rigby said what happened within the company over the next 12 to 18 months was much more important than the first day of market trading.
"But certainly today it's a great boost for staff, customers and investors that the share price has improved."
The NZX and ASX listing, which is the second-biggest local sharemarket float this year after Genesis Energy in April, raised a total of $244.2 million.
Around $230 million of the cash raised will be used to buy Metro's assets from its existing shareholders, which include private equity firms Crescent Capital and Anchorage Capital and senior management. The private equity firms have kept a 18.5 per cent stake in the company following the IPO.
Metro expects net profit of $14.3 million in the year to March 31, 2015, up from $12 million in the same period a year earlier. Full-year sales are forecast to rise to $171.9 million in 2015 from $155.4 million in 2014. Metro expects to pay a dividend of 3.6c per share in the 2015 year, implying a cash yield of 2.1 per cent.
Earlier this month Rigby said the private equity owners had invested about $40 million over the past three years - including upgrading its facilities - and anticipated capital expenditure of about $5 million in the next three to five years.