Trend indicators

Bollinger Bands

A moving average with an upper and a lower band that widen when the market gets jumpy and narrow when it calms down.

用通俗的话解释

Prices spend most of their time near their average. The bands are drawn a set number of "typical distances" (standard deviations) away from the average, so they show what counts as unusually high or low right now, given how volatile the market currently is.

计算方法

The middle line is a 20-candle simple moving average. The bands are placed two standard deviations above and below it. Standard deviation is a measure of how spread out the recent prices are.

Middle = SMA(close, 20)
Upper = Middle + 2 × standard deviation of the last 20 closes
Lower = Middle − 2 × standard deviation of the last 20 closes

如何使用

The squeeze: very narrow bands mean an unusually quiet market, which is often followed by a big move.
In ranges, prices touching the lower band and turning up can be buying points; the upper band, selling points.
In strong trends, prices "walk the band": repeated closes near the upper band are a sign of strength, not a reason to sell.

得出结论

A close outside a band is unusual but not automatically a reversal signal.
The middle band often acts as support in uptrends and resistance in downtrends.

示例

GBPUSD's bands narrow to their tightest in three months. A day later the price closes well above the upper band and the bands open wide: the squeeze has released upwards.

示例中的价格仅作说明。

注意事项

The squeeze tells you a move is likely, not its direction.
Selling every touch of the upper band works in ranges but fails in strong trends.

一点历史

John Bollinger developed the bands in the early 1980s and later wrote "Bollinger on Bollinger Bands" (2001).

仅供学习参考。没有任何指标或形态能预测未来，本页内容均不构成投资建议。