黄金，一度跌破4200美元大关，创四年来最大跌幅！

Core Viewpoint - Spot gold has experienced a significant decline, breaking below $4200, with a drop of 3.8%, marking the largest decline in four years [1]. Price Movements - As of the latest update, spot gold is priced at $4205.25 per ounce, having opened at $4359.15, reached a high of $4375.27, and a low of $4189 [2]. - Spot silver also saw a substantial decline, initially dropping over 6% and currently down 5.04%, priced at $49.76 per ounce [1][2]. Market Reactions - The Shanghai gold futures market has seen the main contract drop by 3%, currently at 959.88 yuan per gram, while the main silver contract fell by 4%, now at 11386.00 yuan per kilogram [3]. - Due to the recent volatility in gold prices, several financial institutions, including Everbright Bank, have implemented stricter measures on gold trading to protect investors [3][5]. Institutional Responses - Everbright Bank announced that starting October 20, it will gradually terminate business relationships with clients who have no positions in gold trading, alongside adjustments to margin requirements [3][10]. - Other banks, such as Industrial Bank, China Merchants Bank, and China Construction Bank, have also issued warnings regarding the increased market risks associated with precious metals [6][8]. Margin Adjustments - The Shanghai Gold Exchange has raised the margin requirements for gold trading contracts, with standard margin ratios for various contracts increasing from 38% to 40% and for silver from 41% to 43% [10][11].