If you want a tidy snapshot of what it’s like investing in the stock market, check out how things have progressed so far in 2025. The lesson is that you can never tell how the stock market will react in the short term, but you can usually depend on it to keep moving higher over the long term. GOBankingRates asked ChatGPT what the biggest mistake is, and here’s what it had to say. Emotional Investing = LossesAccording to ChatGPT, the worst mistake investors make is letting emotions drive their decisions — especially fear and greed. As an example, ChatGPT cited meme stocks, crypto bubbles and speculative tech stocks with no earnings.