The so-called "ten thousand-year income" and "seven-day annualized rate of return" are synonymous with money funds, which mainly invest in short-term government bonds, large negotiable certificates of deposit, commercial bills, bank acceptance bills, repurchase agreements and other tools in the money market. Theoretically, it is possible that "ten thousand shares of income" and "seven-day annualized rate of return" are negative, but the domestic market has never seen "ten thousand shares of income" and "seven-day annualized rate of return" negative. It's just that the values of "ten thousand copies of income" and "seven-day annualized rate of return" fluctuate up and down every day.