1. Summary
  2. To Calculate Bollinger Bands ®
  3. The Squeeze
  4. Illustration of Bollinger Bands ® 
  5. Limitations of Bollinger Bands ® 


Bollinger Bands is a popular fashion. numerous dealers believe the near the prices move to the upper band, the further overbought the request, and the closer the prices move to the lower band, the more oversold the request. John Bollinger has a set of 22 rules to follow when using the bands as a trading system Bollinger bands A Bollinger Band ® is a specialized analysis tool defined by a set of trendlines. They’re colluded as two standard diversions, both appreciatively and negatively, down from a simple moving Average (SMA) of a security’s price and can be acclimated to stoner preferences.  Bollinger Bands ® was developed by specialized dealer John Bollinger and designed to give investors an advanced probability of relating when an asset is oversold or overbought. 

  • Bollinger Bands ® is a specialized analysis tool to induce oversold or overbought signals and was developed by John Bollinger. 
  • Three lines compose Bollinger Bands A simple moving normal, or the middle band, and an upper and lower band. 
  • The upper and lower bands are generally 2 standard diversions/- from a 20-day simple moving normal and can be modified. 
  • When the price continually touches the upper Bollinger Band, it can indicate an overbought signal. 
  • If the price continually touches the lower band it can indicate an oversold signal.

To Calculate Bollinger Bands ®

The first step in calculating Bollinger Bands ® is to cipher the simple moving Average (SMA) of the security, generally using a 20-day SMA. A 20-day SMA pars the ending prices for the first 20 days as the first data point.  The coming data point drops the foremost price, adds the price on day 21 and takes the average, and so on. Next, the standard divagation of the security price will be attained. Standard divagation is a fine dimension of average friction and features prominently in statistics, economics, accounting, and finance.

For a given data set, the standard divagation measures how far figures are from an average value. Standard divagation can be calculated by taking the square root of the friction, which itself is the normal of the squared differences of the mean.  Next, multiply that standard divagation value by two and both add and abate that quantum from each point along the SMA. Those produce the upper and lower bands.   

The Squeeze

The” squeeze” is the central conception of Bollinger Bands ®. When the bands come near together, constricting the moving normally, it’s called a squeeze. A squeeze signals a period of low volatility and is considered by dealers to be an implicit sign of future increased volatility and possible trading openings. Again, the wider piecemeal the bands move, the more likely the chance of a drop-in volatility and the lesser the possibility of exiting a trade. These conditions aren’t trading signals. The bands don’t indicate when the change may take place or in which direction the price could move.  flights roughly 90 of price action occurs between the two bands.  Any route above or below the bands is significant. The route isn’t a trading signal and numerous investors mistake that when the price hits or exceeds one of the bands as a signal to buy or vend. flights do not indicate the direction and extent of the unborn price movement.

Illustration of Bollinger Bands ® 

In the map below, Bollinger Bands ® type the 20-day SMA of the stock with an upper and lower band along with the diurnal movements of the stock’s price. Because standard divagation is a measure of volatility, when the requests come more unpredictable the bands widen; during lower unpredictable ages, the bands contract.

Limitations of Bollinger Bands ® 

Bollinger Bands ® isn’t a standalone trading system but just one index designed to give dealers information regarding price volatility. John Bollinger suggests using them with two or three other non-correlated pointers that give more direct request signals and pointers grounded on different types of data. Some of his favored specialized ways are moving average divergence/ convergence (MACD), on-balance volume, and relative strength index (RSI).  Because Bollinger Bands ® are reckoned from a simple moving normal, they weigh aged price data the same as the most recent, meaning that new information may be adulterated by outdated data. Also, the use of 20-day SMA and 2 standard diversions is a bit arbitrary and may not work for everyone in every situation. Dealers should acclimate their SMA and standard divagation hypotheticals consequently and cover them.