简单地说 -

就是动态地测定某个时间段内离它的最高价（或最低价）的距离 (可以用ATR, 百分比，或固定值来表可以达), 当价格离开这个最高点（或最低点)一定的距离达到预定值 (cutoff point) 时，它就会被触发并调转方向。至于这个预定值, 则因人而异, 要根据各人的实际情况和风险承受能力来设置。

Trailing stop only moves in one direction because they are designed to lock in profit or limit losses. If a 1% trailing stop loss is added to a long position, a sell signal will be issued if the price drops 1% from its latest peak. The trailing stop only moves up once a new peak has been established. Once the trailing stop has moved up, it cannot move back down.