I saw an interesting asset allocation logic: Choosing DRAM in one's 20s, Choose SMH in your 30s, In my 40s, I chose QQ, Choosing VOO in one's 50s, Retired in their 60s. On the surface, ETFs are selected based on age, but in essence, they are configured based on risk tolerance and time window. Choosing DRAM in your 20s is because you can afford to lose. Storage chips experience significant fluctuations, but there is also ample room for long-term growth. You are 25 years old this year, even if you lose 50%, you still have ten years to recover by the age of 35. When young, the most important thing to bet on is high elasticity assets, because the compounding time is long and the odds are more important than the win rate. Choosing SMH in your 30s is because you are starting to take responsibility. Maybe with a mortgage, children, or family. Semiconductor ETFs are more stable than individual stocks, but still have enough growth. SMH covers the global semiconductor industry chain, including leading companies such as NVIDIA and TSMC, as well as equipment and material companies. The aggressiveness is still there, but the dispersion has increased. Choosing QQ in your 40s is because you need balance. There are 100 of the best technology companies in the world within 100 miles of Nasdaq, with a long-term annualization rate of around 12% -15%. At this age, you no longer pursue overnight wealth, but hope for steady asset growth. QQ provides you with most of the growth you want, while also having less volatility than single industry ETFs. Choosing VOO in your 50s is because you are starting to guard. The S&P 500 covers 500 major American companies, with a long-term annualized rate of 10% and a smaller volatility than the Nasdaq 100. You are getting closer to retirement and cannot afford to withdraw more than 50%. VOO is the most stable beta in the US stock market. Retirement in one's 60s is not about not investing, it's about not working for money anymore. Your core position should shift towards cash flow generating assets such as dividends, bonds, and REITs. The goal is to preserve the principal and stabilize withdrawals, rather than continuing to pursue high growth. So age is not the only criterion, time is. How far are you from the day of using money? If there are still 30 years left, it should be radical. If there are still 5 years left, we should be conservative. The most difficult part of investing is not stock selection, but recognizing where one is in life and matching the corresponding risks.