Decades-old investing rule of 60/40 portfolio may be outdated, according to Vanguard. Shift to 40/60 portfolio suggested due to stock market bubble concerns. Bonds offer better returns, less risk in current environment. Framework still holds meaningful equity exposure. Nuanced approach recommended based on age, goals, and risk tolerance.

Read more at Yahoo Finance: The looming AI bubble pop has one investment giant suggesting clients reverse a longstanding rule