US Dollar Index reached its highest quote on Sep 28, 2022 — 114.687 USD. See more data on the US Dollar Index chart.
The lowest ever quote of US Dollar Index is 70.700 USD. It was reached on Mar 17, 2008. See more data on the US Dollar Index chart.
US Dollar Index is just a number that lets you track performance of the instruments comprising the index, so you can't invest in it directly. But you can buy US Dollar Index futures or funds or invest in its components.