With 10 million, earning 5% annually, you’d have 41k per month to spend—that sounds like a solid plan, and it’s achievable. But your retirement portfolio shouldn’t be all stocks, because a 5% return doesn’t come smoothly every year; some years may see losses of 20–30%. If you need to withdraw funds during a market downturn, your principal will erode even faster. This is known as sequence risk. You should allocate your portfolio across cash, fixed income, and some risk assets, so you have funds to cover several years of expenses without being forced to sell stocks at a loss. So while 10 million might be enough, you must manage returns, volatility, and inflation—not just multiply by 5% and call it done.