On the evidence of this sketchy, often slipshod primer, Krefetz (The Smart Investor's Guide, How to Read and Profit from the Financial News) has become an appreciably less responsible source of counsel. Using leverage as his primary perspective, the author provides a once-over-lightly introduction to a welter of markets--real estate, securities, futures, options, gold, foreign currencies. In brief, leverage involves the use of borrowed funds to increase the percentage return on an investment's actual cash commitment; it is, as Krefetz grudgingly concedes, a two-edged sword since adverse price moves can produce losses of proportionate magnitude. Serious investors are well advised to understand the potential rewards as well as downside risks of leverage. The problem here, though, is that Krefetz's cursory coverage pays mainly lip service to the perils of pyramiding, margin, and other forms of leverage. As a practical matter, his largely uncritical enthusiasm could prove hazardous to the financial health of naive marketplace newcomers--his most likely audience. Troublesome as well are the occasional inaccuracies that seem to come with the short-shrift territory. Following a summary rundown on debt instruments, for example, Krefetz offhandedly comments that ""for preservation of capital (bonds) have no equal in the investment world."" This deservedly unheralded theory will come as a surprise to, among others, fixed-income investors whipsawed by the interest-rate swings of recent years. On balance, then, a disappointing and dispensable entry.