Yes!! you should be highly skeptical of anyone saying they've got some great edge -- especially those who are just reading charts lol.And despite all that, the majority of managed mutual funds underperform the market. Same goes for hedge funds:
https://www.linkedin.com/pulse/hedge-funds-vs-sp-500-truth-investment-returns-amr-elharony-hmysf
And I’m guessing most of them use some fairly sophisticated analytical tools, too.
Even guys like John Paulson, who made a pant load of money in 2008 had some less than stellar performance in the following years. Should we be automatically dismissive? Broken clock?