The movements began on Friday, February 25, with the shares sitting at $1.61, and prior to an investor presentation on Wednesday March 9, they gained 14%, or 23c, to hit $1.84.
During that period about 600,000 shares changed hands, compared with about 120,000 the week before.
Interest in the shares has increased since an NZX investor day presentation on February 7, which included a forecast the company may have $75 million to $76 million cash in hand by the end of 2013, and if it cannot find shares worth buying, it may consider distributing the cash to shareholders.
From February 25, the NZX shares gained 31.6% in value - from $1.61 to $2.12 yesterday.
NZX shares generally trade in a daily range of 120,000-130,000, but yesterday turned over about 1.5 million, which followed about 1 million shares the day before.
Craigs Investment Partners broker Peter McIntyre said other than the presentation, interest in NZX shares may have been aroused earlier by bourse merger and acquisition activities in Europe, Asia and the United States and the NZX having talked of the possibility of more initial public offerings in the year ahead; meaning a boost to its own revenue.
He noted the NZX "had not issued itself a speeding ticket", in reference to its ability to request other listed companies to advise the market why their share prices have made major gains or losses.
