Tesla Stock Slumps in October After Second Quarter Surge

Tesla Motors, the best-performing auto stock for much of the year, failed to hang on to some of its gains in October. The shares fell about 17 percent in the month, the biggest such decline of the year as some investors took profits and others may have been concerned about the impact of crash reports that resulted in fires. The decline pared Tesla's value about $4 billion, equal to its market capitalization at the start of the year.