The Elliottician.com publishes a statistics that 65% of stocks gives bad result using Eliott wave theory.
However, Elliott waves work well with high liquidity shares where the crowed (fear and greed) reaction is also present.
Also Elliott Wave Theory (EWT) works with higher probabilty if the past lows of the share are followed by the right patter of the EWT theory.
Note: it requires considerable study time to use the program they provide, though. There are easier to use softwares also.