PT - JOURNAL ARTICLE AU - Jiali Fang AU - Ben Jacobsen AU - Yafeng Qin TI - Practical Applications Report Popularity versus Profitability: <em>Evidence from Bollinger Bands</em> AID - 10.3905/pa.5.4.261 DP - 2018 Apr 30 TA - Practical Applications PG - 1--4 VI - 5 IP - 4 4099 - https://pm-research.com/content/5/4/1.7.short 4100 - https://pm-research.com/content/5/4/1.7.full AB - Despite questions about its profitability, technical analysis remains popular among investors, and some of the most widely used techniques involve Bollinger Bands, which were introduced by John Bollinger in 1983. Since then, Bollinger Bands have gradually gained popularity, especially since 2001 when Bollinger published his book, Bollinger on Bollinger Bands. Within four years, it had been translated into 12 languages, and the English version had been through seven editions.Bollinger Bands are an interesting case study of whether a trading strategy’s popularity affects its profitability, and, if so, how. In their article, Popularity versus Profitability: Evidence from Bollinger Bands, published in the Summer 2017 issue of The Journal of Portfolio Management, Jiali Fang, Ben Jacobsen, and Yafeng Qin investigate the effects of increasing popularity on the profit potential of Bollinger Band–based trading strategies. Their results indicate that potentially profitable trading strategies self-destruct with increasing popularity. As use of Bollinger Bands grew, there was a gradual downward profitability from their use, and since 2001, the year Bollinger’s book was published, Bollinger Bands have largely lost their predictive ability in major stock markets.