美国银行：现金持有水平降至3.9%触发“卖出信号”。

Group 1 - The core viewpoint of the article indicates that the cash holding level of American banks has decreased to 3.9%, which has triggered a "sell signal" [1] Group 2 - The decline in cash holdings suggests a potential shift in investment strategies among banks, possibly indicating a move towards more aggressive asset allocation [1] - This reduction in cash reserves may reflect broader economic trends, including increased lending or investment in higher-yielding assets [1] - The "sell signal" could prompt investors to reassess their positions in bank stocks, considering the implications of lower liquidity [1]