My personal theory is that TA actually works to a certain degree, although more as a kind of self-fulfilling collective delusion. Something along the lines of:
- Analysis guy: "Look at this graph - it's a bells-and-candle figure breaking downwards through MA200! A sales signal!"
- Mindless horde: "Oh noes!"
- *mindless horde sells out in huge numbers, causing a massive plummet in the share price. Analysis guy buys lots of shares.*
- Analysis guy: "Hey, I was right. But look! It's just made a hanged Indian with disjointed shoulder! An obvious buy signal!"
- *mindless horde starts buying again, causing the price to rise. Analysis guy sells his shares and earns the big bucks.*
- Mindless horde: "He's a genius!"
I have a sample rewrite in here. Maybe someone mind have a look?