Success Is Good For Confidence, But May Cloud Your Judgment.(B)(INVESTOR'S CORNER)

Byline: JUAN CARLOS ARANCIBIA

Failing in the stock market often causes dejected investors to withdraw and forfeit new opportunities, even in a powerful rally. But success can sometimes be just as damaging -- if you let it get to your head.

Winning stimulates investors' psyche like nothing else. Score a few 20% to 50% profits, and you may feel invincible. Land a 100% gain, and you may start comparing yourself to Warren Buffett.

Convinced they have the golden touch, overconfident investors ignore signs of weakness. Even after sizable losses, they figure their investing skills will vindicate them and that they'll have the last laugh.

That's how arrogance becomes an enemy as formidable as the popping of a dot-com bubble. A little humility helps keep investors within the bounds of reasonable trading. Even those who enjoy good profits need to adhere to rules.

When a stock starts faltering, don't dismiss sell rules such as declines in heavy volume, loss of support at key moving averages or extended share prices. A catalog of sell signals can be found in the "How To Invest" section of investors.com.

If a stock falls 7% or 8% below your purchase price, sell it immediately. ...