query: What country holds the most U.S. debt?
passage: National debt of the United States
As of October 2018, foreigners owned $6.2trillion of U.S. debt, or approximately 39 percent of the debt held by the public of $16.1trillion and 28 percent of the total debt of $21.8trillion.[53] At the close of 2018, the largest foreign holders[54] were China ($1.13 trillion), Japan ($1.02 trillion), Brazil ($313 billion), and Ireland ($287 billion).[55]
passage: Financial position of the United States
In 1946, the total US debt-to-GDP ratio was 150%, with two-thirds of that held by the federal government. Since 1946, the federal government's debt-to-GDP ratio has since fallen by nearly half, to 54.8% of GDP in 2009. The debt-to-GDP ratio of the financial sector, by contrast, has increased from 1.35% in 1946 to 109.5% of GDP in 2009. The ratio for households has risen nearly as much, from 15.84% of GDP to 95.4% of GDP.