Robot Portfolio Tripped Up As Single Energy Stock Nose-Dives

Robot Portfolio Tripped Up As Single Energy Stock Nose-Dives by John Dorfman, Dorfman Value Investments

A single disastrous energy stock was enough to scuttle my Robot Portfolio last year.

The portfolio suffered a 3.8 percent loss in 2015, dragged down by a 62 percent drop for Atwood Oceanics Inc. (ATW), an offshore driller that suffered as energy prices collapsed. The defeat reduced, but by no means eliminated, this portfolio’s long-term edge over the Standard & Poor’s 500 Index.

The Robot Portfolio is a 10-stock portfolio that I publish each year in my first column of the year. I don’t use judgment in picking the stocks; the selection is purely statistical. Start with all U.S. stocks with a market value of...