The old Copenhagen Stock Exchange was built in the 1620s, also under King Christian the 4th. If you notice the spire, which consists of four intertwining dragon tails and the three crowns at the top of their tails. They symbolize the three Scandinavian countries: Denmark, Norway and Sweden. The three crowns are also repeated on the tower of Christiansborg - and represents the Kalmar Union, which lasted for 150 years as an alliance against German expansion.
In recent times the Old Stock Exchange has been used for gala dinners, conferences, parties and other events and is not open to the public (except one day a year on "culture night" in October. See more here: https://kulturnatten.dk/en/)
Sadly, on April 16th 2024, a fire during renovation work in the main building's copper roof destroyed about half of the building and resulted in the collapse of its iconic "Dragon Spire”. There were no casualties, and luckily several historic artworks from the building's substantial collection, as well as historic furniture, were rescued from the burning building by staff, emergency workers, and passers-by.
NOTICE: Reconstruction works on the building began on 26 September 2024 and is still in progress, which is why it’s not possible to see the building due to scaffolding. The renovation is projected to be done in 2029.