Coin collecting isn't just a hobby, it canbe a big moneymaker for bold physician-investors.According to ,Heritage Auction Galleries sold two coinslast fall for more than $1 million andresold both again in February for nearly15% more. Coin collection experts say thatthe state quarter program brought a lot ofnew blood into the collecting market,which drove up interest and prices. In addition,it is believed that people coming intothe highest-earning years (ie, ages 40through 60) who grew up collecting coins,stamps, comic books, etc, are coming backto the coin market. Collectible currencyusually trades slightly above face value,but those percentages can add up overtime just like other investments. Andthere's big money that can be had, as thecurrent coin and collectible market is valuedat around $40 billion. In addition,research has shown that over the past 62years the collectible market only underperformedthe stock market by about 2%.