Initially the major sovereign funds were set up by oil exporting nations. Now every country with foreign currency reserves can have its own fund.
They manage billions of dollars, shift capital at high speeds (even if their objectives are usually longor extremely long-term) can change the fate of an entire geographical area. The “they” in question are major investment funds, both sovereign and otherwise. Although their names rarely feature in the press, they can be crucial for the development of production in a region.