As you get closer to needing the money from an investment, what happens to your risk tolerance

Risk tolerance gets lower and lower as you get closer to needing the money from your investment.

If you don't need the money for 50 years, you are more likely to take risks in the stock market or other higher risk investments in return for higher rewards. If you need the money tomorrow, you will not be willing to risk it all in the stock market because even though it could double, you might lose it all.