The S&P 500 (^GSPC 0.83%) roared back from its poor performance during the summer, climbing more than 8% to finish the month of October at 2,079. Yet within the S&P 500, some stocks had a greater influence on the index's gains than others. In particular, SanDisk (NASDAQ: SNDK), KLA-Tencor (KLAC 0.33%), and TripAdvisor (TRIP 16.74%) were among the S&P 500 components that had the most upward pressure on the index.
In the following slideshow, you'll learn more about why these three stocks rose so much this month. By watching when the stocks in your portfolio make big moves, you can gather the information you'll need to make smarter decisions about how to respond, and that will help make sure that you don't make mistakes either from doing nothing or by doing the wrong thing.
