Do you value based on a formal Valuation method (such as DCF, or...

Do you value based on a formal Valuation method (such as DCF, or any other acceptable method), or from Financial Statements, or Charts?
Someone very respectable said at a Seminar in US (for which I paid handsomely) said people ask him "how can you possibly know the value of a stock (or other instrument) without doing FA"? And his answer was "because others have already done it for me (wombat:it's a whole industry, right?), and the results of their efforts are reflected in the Chart, which is ultimately the net result of the aggregate activity of all market participants"
It was Mark Douglas, expert on trading psychology (the most difficult part of the game). It's also true he was more of a "trader". But then, I suggest most participants are.
Loot at the image (and its only a portion of the Floor, the size of 3 football fields) - what, exactly, are all those guys doing?