Before liberation, the "Pseudosciaena crocea" in Shanghai's physical gold was converted into the current weight unit of 312.5g. The investment varieties in the gold market are mainly divided into physical gold investment and gold investment derivatives derived from physical gold. Derivatives mainly include gold futures and gold options, and physical gold investment mainly includes gold bars, coins and gold ornaments.

Gold bars come from ancient currency circulation and are more used in the fields of collection and investment. Major banks and financial institutions around the world reserve and circulate their own signature gold bars, such as the standard gold bars of Shanghai Gold Exchange. Gold bars are divided into ounces of gold and grams of gold, and the international gold bar is 400 ounces (12.5 kg).