S&P 500 reaching another record high is exciting, but I don’t think a new high automatically means it’s time to buy aggressively. There are plenty of reasons to remain optimistic. Many of the largest companies in the index continue to report strong earnings, while AI, cloud computing and other technology trends are creating new opportunities for businesses. If corporate earnings continue to grow, today’s expensive-looking valuations could look more reasonable several years from now. Still, I think investors should be careful about getting caught up in the excitement. Markets don’t move higher in a straight line, and periods of strong momentum can make it easy to underestimate the possibility of a correction. Buying simply because everyone else is making money can be a dangerous strateg