美元/日元跌幅扩大，下跌0.7%，报155.93日元

Group 1 - The core point of the article is that the USD/JPY exchange rate has seen a decline, with a drop of 0.7%, currently reported at 155.93 yen [1] Group 2 - The article highlights the regulatory framework surrounding foreign exchange transactions, emphasizing that trading should occur in designated financial institutions as per national regulations [2] - It warns against illegal activities related to foreign exchange trading, including unauthorized buying and selling, which could lead to administrative penalties or criminal charges [2]