Some intraday data series do not contain a buy/sell identifier for trades. As most estimators of transaction costs require this information, an algorithm is necessary to classify trades as buy or sell. When bid/ask quotes (or best buy/sell limit order prices) are available, a natural method is to compare the trade price with the quotes prevailing at the time of the trade. Trades at or above the ask (or best sell limit price) will be classified as buys, trades at or below the bid (or best buy limit price) will be classified as sells. This algorithm will leave trades within the quotes unclassified. Trades within the quotes may be either ‘crosses’ (trades negotiated outside the central market place) or trades where a floor broker or the order book improved on the price of the specialist’s quote, as often happens on hybrid markets like the NYSE. Lee and Ready (1991) show that this algorithm is very reliable and classifies most trades in the same way as the classification based on a comparison with bid and ask quotes.

I’ve mentored several friends and relatives in starting up small businesses. The first years were always a struggle, because they were trying to find ways to efficiently bring in new customers. Once a way was found, things got much easier. Developing a back end (i.e., selling other, usually more-expensive products to existing customers) is relatively easy, as is refining operations.

A typical business start-up of this kind will break even or lose a little money in year one, make a decent salary for the owner in year two, and provide a substantial bonus—in addition to a good, arm’s-length management salary—in year three. After that, it’s usually straight uphill.

So now you know how I feel about stocks, small business, and real estate. Bonds? I love bonds. Especially if you invest in them the way I do: Buy them. Be happy with the guaranteed return. And forget about them.

With this perspective made clear, you will see some sense in the following four model portfolios, each based on a stage of wealth building.

• Stage One: Your investable net worth is less than $25,000.
• Stage Two: Your investable net worth is between $25,000 and $100,000.
• Stage Three: Your investable net worth is more than $100,000 but less than you need to be financially independent.
• Stage Four: You are financially independent.

I’m bullish on entrepreneurship. And I’m at least as bullish on real estate. Stocks are much riskier than real estate—to me—because (1) I’ve lost money investing in stocks and/or stock funds time and again and (2) I’ve seen so many others lose money. Again, I do believe that the stock market has been and will continue to be a pretty good long-term investment. But long term as far as the market goes is a 10- to 20-year time frame. Since we are concerned with getting wealthy in 7 to 15 years (and since the market is currently overvalued, from a fundamentalist’s point of view), I don’t feel confident in stocks.

Nevertheless, since I began actively investing in real estate—about 11 years ago—I have never lost money on a single transaction. The worst two deals I’ve been in since my first big lesson (i.e., disaster) produced yields of 7 percent and 12 percent annually. And that’s not including tax benefits—which were significant. Most of the real estate investments I’ve made have been good to great.