沪金、沪银期货主力合约：10月21日分别跌近3.5%、4%

Group 1 - The core viewpoint of the article highlights a significant decline in the futures market, with Shanghai gold futures main contract dropping nearly 3.5% and Shanghai silver futures main contract falling nearly 4% [1] Group 2 - The article indicates that the declines in gold and silver futures may reflect broader market trends or investor sentiment [1] - The specific percentage changes in the futures contracts suggest increased volatility in the precious metals market [1]