The value of Norway’s sovereign wealth fund, the world’s largest, rose to a record 20 trillion crowns ($1.80 trillion) on Friday, doubling its value in just five years as oil and gas revenue flowed in and stock markets rose.

Built since 1996 as rainy-day savings, the fund owns about 1.5% of all listed stocks globally and has grown to almost four times the size of Norway’s annual gross domestic product, far exceeding original projections.

The fund’s value was comparable in size to the annual GDP of Australia, a country with five times the population of Norway.

 Management, which operates the fund, invests some 70% of assets in global stocks, about 25% in bonds and the rest in real estate and renewable energy plants, with most of its portfolio tracking international market indexes.

Its single biggest holding was in U.S. government bonds, amounting to $136 billion or 7.5% of the fund at June 30, while the top corporate holdings were Microsoft Corp (MSFT.O), opens new tab with $41 billion, Apple Inc (AAPL.O), opens new tabwith $35 billion and Nvidia (NVDA.O), opens new tab at $34 billion.

The fund hit the 10 trillion crowns milestone in October 2019, and was boosted further in the following years by global economic stimulus during the COVID pandemic and by soaring natural gas prices after Russia’s invasion of Ukraine.