According to the Bank for International Settlements' triennial survey, foreign exchange markets turned over an average of $9.6 trillion a day in April 2025. At that pace, the equivalent of a whole year of world GDP changes hands in about a dozen trading days. The US dollar is on one side of about 89% of these trades, even when neither party is American.
That's the estimate from a WHO-led study published in The Lancet in 2024, covering the half-century since the Expanded Programme on Immunization was launched in 1974. It works out to about six lives saved every minute, mostly infants. The measles vaccine alone accounts for around 60% of those lives.
According to the World Gold Council, about 216,000 tonnes of gold have been mined in all of human history. Because gold is so dense (19.3 tonnes per cubic metre), it would fit in a cube about 22 metres on each side, roughly the height of a seven-storey building. Strikingly, about two-thirds of it has been mined since 1950.