An investor's investment horizon should depend on various factors such as their risk appetite, their investment goals, and the type of investments they are making. An investor can choose to have a short-term or a long-term investment horizon.

Short-term investors usually focus on short-term gains and may be willing to take on a higher level of risk in order to gain a higher return in a shorter period of time. Short-term investments may be in areas like high-yielding stocks, real estate, or bond funds. Investors may also be interested in short-term investments to use as a hedge against inflation or downturns in the markets.

Conversely, long-term investors tend to be more focused on capital appreciation over an extended period of time and may be more willing to take on some risks in order to achieve their goals. Long-term investments may include index funds, mutual funds, exchange-traded funds, stocks, bonds, and real estate. These types of investments generally provide investors with more stability and less volatility as compared to more speculative investments.

When deciding on an investment horizon, it is important for investors to consider their risk appetite and their goals. Investors may also want to consider what type of investments to make, as some investments may be better suited for longer-term horizons. Investors should also consider the cost associated with their investments and the time horizon for liquidity, as some investments may not be liquid or able to be sold right away.

Ultimately, an investor's investment horizon should be determined by their own investing goals and financial situation. A longer term horizon usually allows investors to benefit from long-term capital appreciation and allows them to stay invested during market cycles. On the other hand, a shorter-term perspective may be more suitable for investors who want to take advantage of short-term market opportunities or those who have a specific short-term goal they wish to achieve.