I also made the decision to purchase the S&P 500 index fund via Endowus with $40,000 of my CPF Ordinary Account (OA) funds in Sep 2020. It has since generated $2,859.92 (+7.15%) returns within a short time frame of 3 months, beating the 4% Special Account (SA) annual interest rate.
Add that to the dividend income of $25,917 generated by my stocks portfolio would bring the total passive income received to $42,529 for year 2020 (excluding capital appreciation of the stocks portfolio).
Not bad for doing nothing and earning money while sleeping, aye? It's like having a son earn money and him giving you all his paycheck as an allowance, haha. My goal is to earn $50,000 passive income annually because that's how much I think I will need to stop working and live a reasonably comfortable lifestyle.