Moa shares were initially down 29%, or 33c yesterday, trading around 85c, before regaining about half the losses in the afternoon to trade around $1.
Moa lodged a market statement late on Monday signalling the downgrade.
Upon the market opening yesterday, investors aggressively sold off the stock, with a ''brisk'' volume of more than 200,000 shares traded on the NZX close.
Moa managing director Geoff Ross estimated that for the full-year 2014 there would be a volume shortfall of about 30% on the total company target of 195,000 cases of beer, more than 60,000 cases, ''largely due to the sales shortfall in the New Zealand market''.
Moa listed last November, at $1.25 a share, raising a total $16 million; from $1 million in a public offering and $15 million from institutional investors.
Its shares hit a high $1.34 in November and January, but plunged to their lowest yesterday, briefly touching 80c.
Craigs Investment Partners broker Peter McIntyre said the downgrade was a ''surprise for the market''.
''That 30% [downgrade] will be a large [part] of revenue. It's a big disappointment for a growth oriented company,'' Mr McIntyre said.
Mr Ross, former managing director of vodka company 42 Below and chairman of listed candle and bodycare company Ecoya, said that to regain control and momentum in New Zealand, the company was actively negotiating a transition to a new distribution model.
Mr McIntyre said, ''Investors are going to want to see [positive] results from those changes to distribution [in New Zealand and Australia].''
For its last financial result, for the seven months to March, Moa posted a $1.92 million loss on sales of $2.45 million, and overshot forecasts in its prospectus on its earnings before interest, tax, depreciation and amortisation, and spent more on marketing than forecast.
Mr Ross said in Moa's export markets, the US and ''rest of world'' were performing in line with volume expectations.
However, in Australia, which is the smallest of Moa's key markets, sales volumes were also tracking behind targets.
''The company has recently acquired the Australian sales agency rights and intends to manage the Australian business directly,'' Mr Ross said.
