The Open Question Under Fastenal Stock's Price

Fastenal (FAST) stock trades at 43.3 times earnings. The S&P 500 trades at 22.9. Shareholders are clearly paying a premium for a company that keeps growing. Management says its key account strategy mainly drove the latest quarter. These large customers generally carry lower gross margins. Fastenal has not yet shown that it can keep winning those accounts without wearing down the profit it makes on each sale.