Personally, I belive there is no holy grail.
Obviously there are better or worst tools to use, but no perfect one.
Besides, consider that market dynamics are constantly changing, and 99% of all the indicators you see around are not able to adapt to those market changes, or work good only on past years, and slowly loose performance as time advances.
I know a few investment bankers and hedge fund managers (not quant ones, but still), and i asked a similar question some years ago, and they made me aware of how reality really works.
Who has the more advanced quantitative investment tools? Well.., the answer would be some of the big quantitative hedge funds there are (for example
Renaissance Technologies). And are they capable of earning consistently year after year? Well, some of them (like Renaissance Technologies) seem to do so, still 80% of quant hedge funds seem to have been hit deeply in the current US crisis.
Now, continuing with the example of Renaissance Technologies, by far one of the leading hedge funds in quantitative research, can anybody just take a guess at how many millios per year they spend on research? How many physicists, matematicians, economists, engeeniers, etc, they hire for research pourpuses? Well the answer to both questions is, MANY, lots of millions and millions of dollars per year (hundreds), and hundreds of highly qualified research employees (and they are constantly hiring new people).
Still, they have a fairly consistent track record averaging a 35% return since the 90's, but consider this, if their track record didnt get better over the years, and they had to spend all those hundreds of millions dollars in research year after year, then what is all that research doing? Easy answer, they need to stay researching new methods to earn money, because old ones dont work anymore, and those new methods the develop for today, wont work in the future.
Besides, just consider that anything of what those people use, is imposible for a regular person to use. Imposible in the sense that you would need, for example, millions of dollars of liquidity to run their strategies, millions of dollars of equipment to run their models, millions of dollars of personel to mantein them, and so on, and after a while, they would stop working anyway.
Well, i did tell what i dont belive in, now its time to tell what i do belive in.
I belive there are some powerful people, with enough power to be able to manipulate the markets to some extent. Im refering to people like the Rockefellers, Soros, and other big investors and bank owners. Consider that the market moves because there is people to move it. Those with enough power to drive the interests of the mayority, have the biggest and best of all holy grails there is...
Just like i said on the beginning of this post, no holy grail, just better or worst trading tools.
You can be fairly profitable with the right tools, with no need for a holy grail.
Holy grails are just the expectatives and wishes of traders.

Bye