Short answer: No, Power Balance bracelets do not work. There is no measurable benefit from them, and any anecdotal evidence is a result of the placebo effect.
Longer answer: Power bracelets came into style a number of years ago with promises of better endurance and strength. Many people bought them and reported an increase in their energy and flexibility. Power Balance bracelets are made with two holograms on each side of the bracelet. These “resonate with and respond to the natural energy field of the body,” which gives the wearer the purported benefits. However, a study using Division III athletes found that “under the testing conditions used in the current study, there were no significant performance benefits when wearing the Power Balance® bracelet compared to the placebo bracelet.” Furthermore, the Australian Competition and Consumer Commission ordered Power Balance to take down advertising for their bracelets, which promised benefits that had not been proven. There has been a significant decline in the prominence of Power Balance bracelets in media, professional athletics, and common consumer use, largely due to this lack of evidence and clear benefits.