The Four Coins of Luck are four Chinese relics, supposedly given to humanity by the Dragon Kings long ago. The four coins are named, in order, Lu, Shou, Feng, and Fu, representing wealth, longevity, fertility, and happiness. (DotSW.113) According to legend, they have the ability to grant the power of their namesakes to the bearers.
They were apparently part of Dunkelzahn's vast estate and wealth, until his death in 2057. They were given as bequests in Dunkelzahn's Will to various individuals. The First Coin of Luck was given to an old fisherman known as Sun Yat-Sun. The Second Coin of Luck went to the Great Dragon Lung. The Third Coin of Luck went to Sharon Chiang-Wu, the wife of the CEO of Wuxing.
Some of the Coins have changed hands since those bequests. The First Coin of Luck was "acquired" by the group called the Sons of Thunder, resulting in the death of the fisherman due to an ambush from Yakuza operatives posing as Yellow Lotus Triads. From there, it ended up in the hands of Ryumyo, but it disappeared six months later. From there, it was rumored to be delivered to Ghostwalker, where it was stolen by Aztechnology agents. The final whereabouts of the coin remain unknown from there.
The Fourth Coin of luck was within a piece of jade labelled with the Chinese character "Fu" (Happiness), in the unknowing possession of Akira Kageyama, which he found amongst his mother's possessions after her death (which is interesting given the Coins' purported history with Dragon-Kings in crystal palaces under the sea). In 2062, three lesser Eastern Dragons known as Mang, Chiao, and Li (possibly working for Lung, Ryumyo, Wuxing, or just themselves) learned of the Coin and attempted to steal it, but were ultimately unsuccessful. In the end, the shadowrunner Night Owl sold a fake coin and kept the real one.
It is extremely unlucky to sell the coins, they must be given away. People who attempted to sell the coin(s) usually end up dead, while the ones who give them away survive.