A Double Eagle coin is United States currency with a twenty dollar denomination. The Double Eagle coin was first minted in 1849, coinciding with the California Gold Rush. There are two major types of Double Eagle coins, each with 3 minor variations. Double Eagle coins are .900 fine (90% pure) and contain 0.9675 oz of gold and 10% copper. The first to be minted is known as the Liberty Head Coronet. This version of the coin was in production from 1850 until the coin was redesigned in 1907. The Double Eagle went out of production entirely when the price of gold was raised in 1933.

In 1907, the Double Eagle coin was designed by the premiere American sculptor August Saint-Gaudens at President Theodore Roosevelt's request. This new version of the coin is known as the Saint Gaudens Double Eagle. Saint-Gaudens' initial design for the double eagle was an ultra-high relief that didn't stack correctly for banking purposes. This led to a high relief version and eventually a low relief version that was put into circulation and mass production.

St. Gaudens coins are some of the most heralded coins in all of the United States gold coins because of their beautiful artwork. Less than thirteen thousand coins were struck with the high relief version of the artwork, making them quite rare. As many as 8 million coins were struck in some years, but many of the coins were destroyed after the coin was taken out of circulation in 1933. Because of this, an exceptionally rare 1933 Double Eagle was bought at auction for $7,590,020. However in general, the coin is very plentiful and often available in very good condition because they were mostly used in trades with foreign powers. St. Gaudens coins are good investments when they sell at spot or small premiums above spot. The 1908 no motto St. Gaudens gold coin is one of the most common available, which makes it a good place to start a collection on a budget.