主题：咨询一下河友们，美国股市的交易规矩？ -- 剑心浪客

in my TDAmeritrade account. In May, I bought a fund with my own money. Unfortunately that fund dropped a little bit the second day and I saw red big words when I logged in telling me that I lost money in Margin and must put in more money blah..blah. That was the first time I saw that in my TD account after years of trade. But I could not recall using any margin. I thought I might have chosen margin instead of cash by mistake when I had entered my order. I sold my fund immediately to avoid margin call. What a fool I was! In June I bought another fund and the same thing happened. I was quite certain that I used my own money so I called TD. I was told that since my account is a margin account, TD will use margin to cover whatever I bought at the first place, and then after 3 days my own cash will be deducted to cover margin.As long as I have enough money in my cash account, I will not be charged margin interest,etc. I believe this is a new rule after TD and Ameritrade's merge.