Core Insights - Warren Buffett's 90/10 rule suggests allocating 90% of funds to a low-cost S&P 500 index fund and 10% to short-term government bonds, designed specifically for his wife's long-term financial needs [2][8] - The rule is seen as a simple strategy for investors to capture market returns without active management, but it may not be suitable for all retirees [3][4] Group 1 - The 90/10 rule amplifies sequence of returns risk, which is particularly dangerous for retirees who need immediate access to funds for living expenses [5] - The stock market has changed significantly since Buffett's original advice in 2013, making it essential for investors to consider their own financial situations and time horizons [6] - Benjamin Graham, Buffett's mentor, recommended a more flexible allocation of 25% to 75% between stocks and bonds, allowing for adjustments based on market conditions [7][8]