This might explain it. From NZ Herald 17 April "StockTakes"...

This might explain it. From NZ Herald 17 April "StockTakes" column

ALL THAT GLISTERS

Shares in NZX/ASX dual-listed goldminer OceanaGold have been making healthy gains since December when they hit a low of 22c.

They closed steady at 81c yesterday, reaching as high as $1.18 early last month.

February was a month of unusually high turnover for the stock. All of this prompted a "please explain" from the ASX on February 19.

The company responded, pointing towards the strengthening gold price, the weakening New Zealand dollar, its own commentary late last year indicating increased production and lower costs, and finally the release of a favourable research report in January.

But Stock Takes was this week informed of another factor that may have had an influence, namely erroneous information that was published on the NZX website and supplied to at least one local broker suggesting the company was about to pay a A25c one-off dividend.

A local investor contacted us saying he'd initially thought this was too good to be true, but his broker assured him, based on data supplied by their information provider, that it was the case.

The investor thought he'd have some of that and bought shares in anticipation of the payout, only to find out the dividend was non-existent after all.

To the firm's credit, Stock Takes understands it has made good on the investor's losses, but has done so out of its own pocket, and there is no comeback on the company that supplied the information.

The investor says the heavy turnover in the stock around the time that he spotted the bogus dividend information suggested other investors were similarly wrong-footed.