Gold futures are different from spot gold. According to the custom of international on-site trading, the trading rules stipulate the limit of price increase and decrease. The daily price of gold futures is limited to 3%. For example, the settlement price of the previous day was 300 yuan/gram, with a daily limit of 309 yuan/gram and a daily limit of 29/kloc-0 yuan/gram. However, if the daily limit is closed within 5 minutes before today's closing. Then the next day's price limit was extended to 6%. If the board is sealed again the next day, it will be expanded to 9% on the third day. Therefore, the price limit of gold is 3%, 6% and 9%.