FI Series Part III: Financial Independence, 4% Rule, Index funds
Let’s put some substance behind the idea of financial independence (FI).
What is financial independence?
Financial independence means reaching a level of financial security where you no longer need a traditional 9–5 job to cover your basic living expenses. Your investments—or other sources of income—are able to support you. Working becomes a choice, not a necessity.
How do you achieve financial independence?
The path I’m taking is through investing in the US total stock market index fund.
This means investing in stocks, but instead of trying to pick individual stocks and hoping I get lucky, I invest in the entire American economy. Index funds allow me to own small pieces of many companies at once, reducing risk and relying on long-term growth rather than short-term bets.
To support this approach, I save about 40–50% of my income by living frugally. In simple terms, I’ve designed my life so I can live on about half of what I earn.
For example:
• If I earn $1,000 per week, I save $400–$500 and live on $500–$600. • If I earn $2,000 per paycheck, I save $800–$1,000.
The money I save goes into an investment vehicle such as the US total stock market index fund or the S&P 500 index fund, which historically grows at an average of 8–10% per year over the long term.
When are you financially independent?
A commonly used guideline is the 4% rule. If you can cover your annual living expenses by withdrawing 4% of your invested savings each year, you are considered financially independent.
Here’s an example:
If your annual expenses—including rent, food, phone, and other basics—total $20,000, you would need about $500,000 invested. Withdrawing 4% of $500,000 gives you $20,000 per year, enough to cover your expenses without relying on a paycheck.
This is a simplified explanation. Real life includes additional considerations such as taxes, inflation, market ups and downs, healthcare, and investment fees. But the core idea remains the same: spend less than you earn, invest the difference, and give your money time to grow.
Financial independence isn’t about being wealthy. It’s about building enough security to live life on your own terms.
~ Bai, Wednesday, February 18, 2026, NorCal