Digging into my quotes file:

4/19/2020
Charlie: "Warren wants to keep Berkshire safe for people who have 90% of their net worth invested in it. We're always going to be on the safe side. That doesn't mean we couldn't do something pretty aggressive or seize some opportunity. But basically we will be fairly conservative. And we'll emerge on the other side very strong."

2020AM @$183
Warren: "Our airline position was a mistake. Berkshire is worth less today because I took that position than if I hadn't. There other decisions like that, and it is not more compelling to buy the shares now [$183] than it was when we were buying them [$203-$226]. It's not less compelling. I mean it's a wash. But the price has not gotten to a level or not been at a level where it really feels way better to us than other things, including the option value of money to step up in a big, big way."

[They bought $23bn worth after this in 2020, and another $27bn in 2021]

2023 AM
Warren: “What we'd really like to do is buy great businesses. If we could buy a company for $50bn or $75bn, $100bn, we could do it”.