One reason the U.S. doesn't have large-denomination notes is that big bills make it easier to move and hide large amounts of cash. The largest denomination currently issued is the $100 bill. The Nixon administration cited low usage when retiring the $500–$10,000 notes in 1969, but since then, the policy rationale against reintroducing bigger denominations is that high-value notes are a tool for money laundering, tax evasion, drug trafficking, and corruption. The idea is they let you move and store large sums with far less bulk. The ECB followed the same logic in 2016 when it stopped issuing the €500 note, citing concerns it was being used for illicit activity.(Nick Timiraos)