Not Diversifying

Putting all your money in one stock, sector, or asset class is gambling, not investing. Enron employees who held company stock in their 401(k) lost everything in 2001. Crypto maximalists who went 100% Bitcoin in November 2021 ($69K) watched it drop to $16K by 2022. The solution is embarrassingly simple: a single total-market index fund (VTI) gives you exposure to 4,000+ US stocks. Add an international fund (VXUS) and a bond fund (BND) and you have a portfolio that Warren Buffett, Jack Bogle, and most Nobel laureates in economics would approve of. Diversification is "the only free lunch in investing" — Harry Markowitz.