There have been hedge funds and other investment groups that claim to use RV. (At least according to Google and pro-RV books.) They also claim to be able to beat the market. Based on those anecdotes, I think any hedge fund that thinks they can use RV will publicly brag about it to get more investors.

None of these groups can replicate their results beyond the initial claims. This is strong evidence that positive results in RV are just due to selection bias, specifically https://en.wikipedia.org/wiki/Publication_bias. If those investment groups could actually replicate their results, they would still be major names and others would be actively trying to copy them since it should only take a couple of millions of dollars to find capable RV candidates.

The non-skeptical view is that if people try to predict the stock market via RV, they will interfere with the future and their prediction ability will decrease. But when weighing this hypothesis against the hypothesis that RV is just selection bias, the latter wins due to Occam's Razor.