Most expensive banknote sold at auction

The most expensive banknote sold at auction is an 1890 United States $1,000 Treasury Note, which sold for $3.29 million (£2.6 million) at Heritage Auctions (USA) on 10 January 2014.

The note is known as the "Grand Watermelon" note, due to the three prominent zeros on the reverse that resemble the fruit. The notes are extremely rare, and only three specimens are available to collectors.