American Financial Group shareholders are up 5.6% for the year (even including dividends). But that was short of the market average. If we look back over five years, the returns are even better, coming in at 28% per year for five years. Maybe the share price is just taking a breather while the business executes on its growth strategy. It's always interesting to track share price performance over the longer term. But to understand American Financial Group better, we need to consider many other factors. For example, we've discovered 1 warning sign for American Financial Group that you should be aware of before investing here.