What are the biggest mistakes first-time investors make?

First-time investors most commonly let emotions drive decisions, buying when markets are high out of excitement and selling during downturns out of fear. This buy-high, sell-low pattern destroys returns. They also try to time the market or chase recent top performers, not realizing past performance rarely predicts future results. Other frequent mistakes include not diversifying enough, putting too much into a single stock or sector, and ignoring fees that quietly erode gains over time. Many beginners also invest money they might need soon, forcing them to sell at bad times. Starting too late or waiting for the "perfect moment" is itself a costly error. Consistency, patience, and low-cost index funds solve most of these problems for the majority of new investors.