Stock investors concerned about whether high debt will burden their equities in a downturn may be wise to look at cash-rich, low-debt companies such as Gilead Sciences Inc. (GILD), KLA-Tencor Corp. (KLAC), Teradyne Inc. (TER), and Gentex Corp. (GNTX). The outlook for the U.S. economy remains uncertain even after the Federal Reserve announced on Wednesday that it would hold off on rate hikes for the moment.