你可以随时设个order买或卖Mutual funds, 但这个买卖要到股市收盘后才能执行.

"You can enter an order to buy or sell mutual fund shares at any time, but your trade won't be executed until the closing of the current trading session or the next trading session if you place your order after hours. The price you realize will be the NAV that is calculated after the market closes."

https://www.schwab.com/learn/story/6-things-to-know-about-how-mutual-funds-work#:~:text=You%20can%20enter%20an%20order,calculated%20after%20the%20market%20closes.?