Is it always a waste of money to keep liquidity in hand? In our opinion, the answer is no. This should not become a regular habit and the reason why this money is not invested should not be that you didn't have time to invest it. But there are some cases in which it can make sense to keep some liquidity, notably if you believe that a great investment opportunity is going to come up. Warren Buffett's firm Berkshire Hathaway, for instance, is sitting on a record amount of cash.