Opinion Learning P/E Ratio vs Earning Many would argue, like William O'Neil, that just because a stock trading at the low end of the yearly P/E range does not make it a good investment. They would continue to argue we should consider whether the rate of change in earning is substantially increasing or decreasing. They would however use P/E to guess the potential price objective of a growth over the next 6 to 18 months based on its estimated future earnings. TL/DR Earnings and future earnings are the leading indicator when utilizing the P/E ratio in stock valuation.