Norway’s sovereign wealth fund earned more than £90bn during 2020 as the wave of central bank stimulus provided to counter the effects of the coronavirus pandemic pushed up the value of shares and other assets. The fund, built with the revenues from its oilfields, gained 10.9% in value during the year, Norway’s central bank said on Thursday. The total gain was worth 1.07tn kroner (£91bn). However, the fund’s head said the appetite for market risk was “high” and warned that the buoyant investor mood would at some point come to an end. Nicolai Tangen told the Financial Times that the retail investor boom – exemplified by the GameStop furore – and the emergence of blank-cheque special purpose acquisition companies were signs of a high-risk market environment. “The positive developments we have seen in markets can’t, of course, go on forever,” he said. “What we are seeing now is indicative of the type of risk appetite there is. And the risk appetite is high. You see it through this type of situation such as Spacs [special purpose acquisition companies] and retail investors.” Norway founded the Government Pension Fund Global, also known as the oil fund, in 1990. It has grown into one of the biggest single stores of wealth in the world, and the largest sovereign wealth fund controlled by a country on behalf of its citizens. In 2017 its value surpassed $1tn (£730bn) for the first time. At that point the Economist magazine calculated that the citizens of Norway owned more than 1% of all the world’s shares. Despite its roots in oil wealth, the fund has turned in a different direction in recent years, including a 2019 pledge to divest its ownership of oil and gas producers’ shares. The 10.9% gain for the fund was not a particularly extraordinary performance during a year in which the US benchmark stock market index, the S&P 500, gained more than 16%. However, the vast size of the fund meant the increase was notable. Its value on 31 December reached 10.9tn kroner, or £923bn – equal to assets worth £170,000 for each of Norway’s 5.3 million inhabitants. Global stock markets plunged in early 2020 as the extent of the coronavirus pandemic became clear, but staged a remarkable rebound from the end of March as central banks stepped in with huge stimulus efforts. That stimulus is thought by many economists and investors to have inflated the prices of many assets, such as those in companies such as Tesla, the electric carmaker, or GameStop, the US video game retailer at the centre of a retail investor frenzy. Some 72.8% of the fund was invested in equities, 2.5% in unlisted property, and 24.7% in fixed income such as government and corporate bonds. US technology in particular helped the fund, said Norway’s central bank, which manages it.