Not only was the oil exploration and production company the top performer in the six months ended June, it was also the best performer in the June month, the three months ended June and the year ended June.
The month return was 11.9%, the three-month return 38.3%, the six-month return 62.3% and the annual return 71.3%.
Forsyth Barr broker Peter Young said NZOG had gone from strength to strength in the past 18 months thanks to the rising oil price. The Tui well was producing well ahead of forecasts with Tui reserves 68% higher than forecasts.
The company was also sitting on a "war chest" of $180 million from recent conversion of options and had stated it was pursuing new investments.
NZOG's market capitalisation had grown from about $265 million in January to $708 million yesterday.
"The highest valuation in the market I have seen is $2.56 a share so trading at $1.69 is deemed to be cheap," he said.
Others to perform well in the first half of this calendar year were fishing company Sanford (29.2%), farm supplier PGG-Wrightson (15.8%), overseas dairy farmer NZ Farming Systems Uruguay (7.4%) and TelstraClear (5.2%).
Hellaby Holdings and Hallenstein Glasson were the worst performers on the NZX-50 this year with Hellaby Holdings showing a -45% return for the six months ended June and a -58.7% return for the year.
Hallenstein Glasson had a -26.7% return for the June month and a -30.8% return for the three-month period but did not feature in the six-month or annual worst-performer tables.
Other poor performers in the six months were Pumpkin Patch (-43.9%), Fletcher Building (-42.4%) Michael Hill International (-39.8%) and Fisher & Paykel Appliances (-39.3%).
Mr Young said it was easy to see that it had not been a good year for the top 50 index.
The one-year return for the NZX-50 was -24.6%, a greater fall than major indices like the Dow Jones Industrial Average (-15.4%), the FTSE-100 (-14.9%) and the ASX-200 (-13.4%).
The ASX-200 would probably have been down much more if it had not been for the huge amount of resource stocks in the index, he said.
BHP was up 26% in the year ended July 1 and Rio Tinto was up 40% in the same period.
"Quite clearly, there are some extremely cheap stocks on the New Zealand market, but with all the worries overseas regarding potentially more large writedowns by Lehman Brothers and Citibank, people are keeping away from our market.
"There was also evidence last month of overseas fund managers selling New Zealand stocks en masse, which certainly doesn't help market sentiment."
The value of shares traded on the stock exchange in June fell 11% in June to $2.58 billion from June last year.
The number of trades fell 3% and the average daily value traded was $129 million.
The sharemarket plunged 12% during June.
The number of trades for the NZSX market was 47,946 for June 2008, down 2% on the same period last year, while the value traded dropped 13%.
Mr Young said finding an entry point was going to be the key to entering the market but it was unlikely to happen until there was an easing in the Reserve Bank's official cash rate.
"It's fairly tough at the moment but there will come a time to enter the market. If you have a long-term view, there are some very good stocks in New Zealand that will give you good capital growth as well as income."
The price of oil needed to pull back significantly to help lift the market but that was unlikely to happen in the near-term with some analysts signalling it could soon hit $US170 ($NZ222) a barrel.
With the new portfolio investment entity (PIE) tax laws now in force, property stocks were attractive to 33% and 39% tax payers as the maximum tax they would pay on their dividends was 30%, he said.
