<human>:  What is the optimal way to invest a lump sum of money for long-term gains?
<bot>: The optimal way to invest a lump sum of money for long-term gains is to diversify your investments and create a balanced portfolio. This can be done by investing in a mix of assets, such as stocks, bonds, mutual funds, and exchange-traded funds. Having a diverse portfolio helps spread out your risk, while earning potential higher returns over the long-term. Investing regularly over a period of time is another way to build wealth gradually and reduce market risk. It also helps you to focus on long-term goals rather than short-term speculation.