I was reading a story in The Wall Street Journal recently about Block Trading, Inc., a now-defunct day-trading firm based in Houston. Day-trading firms, which offer individual investors the ability to do short-term trading on sophisticated computer systems, have sprung up like weeds in recent years. (I think the weed analogy is especially apt, as you'll soon see.)

The article said that the state of Massachusetts has brought a wide-ranging complaint against Block Trading. The complaint alleges that the firm lured customers by trumpeting the huge profit potential of day trading while not adequately warning of the risks. What I found especially interesting is that, according to the complaint, only one of the firm's 68 accounts in its Boston office made money during the year it was opened.

Just one.

The notion that individual investors can trade their way to lasting riches is a laughable one, in my opinion. Oh sure, occasionally a trader might guess right and take home a few bucks. Even the slots occasionally reward the sucker who pumps coins into them enough times. But over time, your chances of building wealth-trading stocks are about the same as hitting a jackpot in Las Vegas.

Why is trading stocks successfully so difficult? For starters, frequent stock trades create transaction costs and tax liabilities - two things that erode the value of portfolios. Furthermore, trading requires you to be right about both the stock and the timing of your purchase and sale. In other words, it's not enough to pick the right stock; you have to pick the right stock and be perfect on your timing. That's asking a lot, especially over time.

What I find perhaps the most offensive about day trading - or weekly or monthly trading - is that the strategy implies that traders have many, many, many good investment ideas. After all, if you're trading 30 or 50 or 100 or, in some traders' cases, a 1000 or more times in a single year, doesn't it imply that you feel each trade is a good idea, a potential winner? Let's face it - most of us probably won't have 30 good ideas about anything, let alone stocks, in our lifetimes. Warren Buffett, arguably the greatest investor of our time, owns less than two-dozen stocks, many of which he's held for several years. If Warren Buffett has only a relatively few good ideas, why should any investor believe that he or she has 50 or more good investment ideas per year?

Good investment ideas don't grow on trees. If you're fortunate enough to have what you think are three or six or 12 good investment ideas, let time work its magic on them. Remember: Good investment ideas have longer shelf lives than a day, a week, or even a year.

When I discuss the evils of trading in this column, I feel a little like the pastor preaching to the choir. You already know the sermon. The fact that you're interested in buying stocks via BUYandHOLD indicates that you've "seen the light" and believe a long-term, buy-and-hold investment strategy is the way to build wealth in the stock market. Still, I know how tempting trading can be, especially now when anyone can make $5 or $10 trades over the Internet. I'm sure many of you have friends who claim to have reaped huge reward from trading stocks. Perhaps you're thinking of dipping your toe into the trading waters. My advice - don't swim in that pool.

The phenomenon of day trading arose from the intersection of the Internet and extraordinary stock market returns from 1995-1997. Given the unprecedented returns during those three years, it would have been difficult to not make money regardless of what hair-brained investment strategy you used. As the markets return to more traditional returns, my guess is that those friends who now crow about their trading profits will be licking their wounds, or perhaps even be out of the market altogether. Believe me, it will happen.

Just ask the customers of Block Trading.