By Richard Russell in Dow Theory Letters:
Markets can be compared with gambling at Las Vegas. When you gamble at Vegas, you are bucking the house odds. Which is why if you play long enough at Vegas, you will always lose your money. Vegas is stacked that way. Las Vegas is constructed to separate players from their money. The stock market is a bit classier. When you buy stocks, you are at least buying something. It feels good to say, "I bought 500 shares of Johnson & Johnson."
When you put your money down at Las Vegas, you are not buying anything, but with a slim chance (the odds are against you) of winning more than you put down. Las Vegas is one of the few places where you pay your dollars, and are guaranteed to receive NOTHING of any value.
"Gambling is a tax on people who don't understand money," that's my favorite adage about gambling. Investing in the stock market is a long-term tax on people who want something (profits) without doing any real work for those imaginary profits.