Rare coins might be cool to look at, but their monetary value is largely based on the same thing as any other asset: supply and demand. Which are worth buying?

A new $1 coin featuring Donald Trump became available in September, but it contains no precious metals. Unlike the Trump coin, gold bullion coins are made of gold and are used for investment purposes.

To celebrate the nation's 200th birthday back in 1976, the U.S. Mint released a series of commemorative coins, including a few quarters that are wildly valuable today. If you're looking for a fun, ...