Imagine if you had invested S$100,000, the bulk of your savings, into the Straits Times Index (SGX: ^STI) when it reached a peak of 5,041 on 23 February 2026. Why Investing at the Peak Feels So PainfulInvestors tend to feel the pain of losses more intensely than the satisfaction of equivalent gains due to loss aversion. Professionals also struggle to time markets consistently, and "best" timings are only obvious in hindsight. Fear also makes investors wait "forever" for lower prices. Say you have already invested a large sum during the STI peak; here are three options for you:Option 1: Stay InvestedIf you are still confident in your investment thesis, the best action may be to simply do nothing.