Elevated valuations don't guarantee a market crash, but they can prompt investors to think more carefully about diversification. After all, Berkshire has been selling more stocks than it's buying while its cash pile continues to grow. A high-yield account like a Wealthfront Cash Account can be a great place to grow your uninvested cash, offering both competitive interest rates and easy access to your money when you need it. Buffett has not publicly warned that a market crash is imminent, nor has Berkshire said its growing cash balance is intended to prepare for one. The takeaway here is that having cash available gives Berkshire flexibility if markets stumble or attractive acquisitions emerge from market chaos.