Admit it. You're tempted to quit your 9-to-5 and begin day trading stocks for a living. You hear it's easy money. Easy BIG money. You know a friend who knows a friend who knows a friend who says he's making a fortune day trading stocks on his home computer. Cutting a fat hog, your friend says. And you think to yourself, "Hey, if he can do it (and he was driving a truck two months ago), why can't I get rich day trading stocks."

The intersection of the Internet and the decade-long bull market has spawned a nation of day traders. These "investors" - and I use the term loosely - huddle in front of their computers each day, mouse in hand, clicking off trade after trade via their favorite online broker. Whether they're making money or not is hard to discern. Oh sure, you hear about somebody who is supposedly making six figures trading stocks. But these stories kind of trickle in much the same as the stories of friends who win the lottery or a jackpot in Vegas.

The fact is that the day trading "fortunes" that you hear about on TV or read about in newspapers or the plethora of books that have been published on the subject mask this simple fact:

Day trading stocks doesn't work.

I'm not saying that there isn't some soul out there who is actually making a nice piece of change from day trading stocks. However, the average day-trading Joe or Jane is getting killed trading stocks. Why doesn't daytrading work? Oh, let me count the ways:

	A mountain of academic work has shown that trading investments is a fool's game. Over time, it is almost impossible, via trading, to make up for the portfolio value lost through transaction costs and tax liabilities. You just have to make too many decisions day trading stocks, and the likelihood of you making more good decisions than bad decisions is very remote.
	Day trading is a very arrogant form of investing, and arrogance usually leads to disaster. Daytraders, merely by making many trades in a single day, are implying that they have many wonderful investment ideas. However, most investors probably have only three or four really good investment ideas in a lifetime. To assume that you can have many good investment ideas each day is the highest form of investor arrogance.
	Frequently buying and selling stocks limits your upside potential. That's important since it is usually only a couple of stocks that make any money for investors over time. If you are constantly selling stocks after they rise 25% or 50% (if you're lucky), you'll never own the stock that goes up 500% or 5000%. Those are the stocks that bail out the rest of your mistakes. Those are the stocks that truly make you rich. Daytraders will never own those stocks.
	A famous football coach once said the following about the forward pass - "Three things can happen, and two of them are bad." Frequently selling stocks has the same problems. When you sell stocks, you incur a transaction cost, and that's bad. You also potentially incur a tax liability, and that's bad. You face reinvestment risk, and that can potentially be bad. Indeed, studies have shown that individual investors generally sell the stocks they should be buying and buy the stocks they should be selling. Smart investors sell stocks sparingly.

Telling people that daytrading doesn't work, however, is rather difficult these days since investors tend to draw their finish lines rather snugly. Indeed, someone who makes money one day deems himself or herself a successful daytrader. Unfortunately, investing is a marathon, not a sprint, and when daytraders draw themselves more realistic finish lines, I think they'll come up far short relative to a buy-and-hold investor.

Thus, if you've just given your employer your notice and are heading out to Best Buy to pick up a computer in order to day trade, here's a piece of advice - Don't give up your day job.