Thousands of investors have sold their shares in the three Government-owned power companies since they were first listed.
There are now 24,700 fewer retail shareholders in Mighty River, Genesis and Meridian combined, compared to when they first floated on the sharemarket.
More than 234,600 investors bought shares in the three power companies, Mighty River, Genesis Energy and Meridian, when they were floated on the sharemarket in 2013 and 2014.
Executive director at Milford Asset Management Brian Gaynor said it was quite normal for shareholder numbers to fall after an IPO and the three power companies had not suffered as much as Contact Energy did following its listing in 1999.
Contact Energy originally had 225,000 individual shareholders but that fell to 164,000 just 18 months later. As of August, Contact had just 69,600 shareholders.
Genesis suffered the biggest losses in retail shareholder numbers, with the company losing 12,000 investors since its listing in April this year.
Mighty River Power has lost 1,748 individual shareholders since listing on the sharemarket in May last year.
Meridian Energy has lost 11,000 shareholders since listing in October last year, most of them retail investors.
Head of wealth research at Craigs Investment Partners Mark Lister, said Meridian investors would have to pay a second installment in 2015 for the share they bought at the IPO, and this may have encouraged some people to sell their shares before that happened.
He said many investors had also sold their shares to free up funds and make room in their portfolios for the 16 other companies that have listed on the sharemarket this year.
Mr Lister, said while overall shareholder numbers had fallen, New Zealand ownership in the three companies had generally risen.
"New Zealand institutions have generally increased their holdings and a lot of this will be Kiwisaver funds. Many New Zealanders, including those retail investors who have sold their shares since IPO, will actually own more shares via their Kiwisaver schemes, whether they are aware of it or not," he said.
Mr Lister said returns had been exceptional for all three of these companies since they listed and that was likely to be one of the reasons why some people had sold their shares.
"Since IPO, Meridian is up 93 per cent, Genesis is up 38 per cent and Mighty River is up 34 per cent. These are phenomenal returns and its not surprising that a few people have been tempted to sell some shares and book some very healthy profits."
Retail investors who bought Genesis and Mighty River shares at their IPO were eligible to receive some free bonus shares in 2015.