Alright, let's get this straight. . .
Genics: You must understand why each tic is going up and down then? There is no possible way to understand every dip/pop/trend in the intraday movement (almost entirely random). Often times you hear the news say, "blah blah dow dropped 250 pts due to international struggles yada yada"....Do people REALLY sell based off of solid reasoning (technical or fundamental)? Rarely! I sell when my indicators tell me to...But my indicators are based off of other humans random decisions! It works! And I don't have to "understand" it, I merely see the opportunity in the chart, and trade it. The only doubts I have are people who are scalping the shortest timeframes. I mean, I could buy the market and sell it for a few ticks later just because I feel like the market is moving up...that would be a random transaction...
As a trader, you should know this: we do not need to understand a movement. We do not need to justify it, it's absurd to even try! We trade the movement and let the economists explain it in terms of unemployment, earnings, new housing sales, interest rates, rate cuts, bail out packages, political struggles, etc...
Nobody is arguing the market is 100% random. But we can also assume some humans might actually be choosing to make random trades. Why? Because we're talking about human emotions and opinions (desire to make profit or perhaps "gamble" or get even with the SPOUSE!).
And if size dictates the market on the short term, guess what? A random decision made by a large buyer/seller easily moves the market based off of their arbitrary feelings/emotions/data (if any!).
We can count on improbable events...we can count on the market to surprise us...
And seriously, if people actually "understood" the markets, why would they make such terrible decisions ?????? I think emotions control the market, which makes it prone to random movement.
As humans we always try to "attach" meaning to everything. Do we really know the meaning behind certain moves in the intraday-or do we just "Attach" a meaning to it ??? It is likely the second. The Dow does not rally because of specific reasons (sometimes maybe)....how many traders will jump onto a move without any "understanding" of the move? Thousands! Millions!
I know for myself...I could care less about understanding a last minute rally in the Dow...I just start BUYING! I see my technical resistance breaking out-I go ahead and buy! But why does it move...that is the debate 50% random 50% rationale (TA and/or Fundamental).
It's kind of like saying, Poker is never random. Poker is partially random. The cards you get are drawn out of random and delt to each player...the flop, the turn and the river are all random cards, but how do we profit? Our interpretation of our odds and the possible outcomes of this "random" game.