Diversification is the best strategy to deal with emotions while investing. When you diversify the risk is spread across multiple assets. Few of your investments may underperform or you may take wrong or emotional decisions for some of your investments. In such cases, the better performing investments in your portfolio may make up for wrong or emotional decisions which you took. And also, you have a long term investment plans to overcome your emotions. When you focus on long term goals, you ignore temporary market fluctuations. Meanwhile, you also benefit from the power of compounding. Lastly, seek professional advice from investment advisors, CFPs and mutual fund distributors. Because they help you make rational and unbiased decisions.