The result of a merger of six Danish utilities in 2006, Dong Energy has transformed itself from being one of Europe's most coal-intensive energy groups into a global renewable energy leader.
While more than half its income now comes from renewable sources, it still makes money from oil and gas production, mostly in Norway and Denmark.
Its offshore wind farm operation is the largest in Northern Europe, where Denmark, Britain and Germany are its biggest markets, but much of the industry relies on government subsidies.
Sydbank analyst Morten Imsgard said he thought the IPO price had been "relatively high in relation to the risks there are, after all, in relation to Dong's future business model in the offshore wind turbine industry."
Dong's "ability to remain the leading developer of offshore wind farms" was especially important going forward, he told news agency Ritzau.
Denmark's former centre-left government nearly collapsed in 2014 when it sold an 18 percent stake in Dong to a consortium led by US investment bank Goldman Sachs, prompting the leftist Socialist People's Party to leave the government amid claims that the bank had been given unusually favourable terms.
The bank on Thursday argued that its know-how from other energy investments had been crucial for Dong's transformation, and that the price it paid reflected the company's situation at the time.
"You have to remember that there was a high risk associated with investing in Dong," a Goldman partner who sits on the board of Dong, told Danish daily Berlingske, adding that there had been major changes in the energy sector since then.
"Dong was and is a mix of risks and possibilities," he said.
After the company's bourse debut, in which no new shares were issued, the Danish government's stake stands at 50.4 percent, down from a previous holding of 58.8 percent, while Goldman Sachs' stake has fallen from 17.9 percent to 14.7 percent.
The Danish company made a 12.1 billion kroner loss last year, as the value of its oil and gas assets took a hit from lower oil prices.