Buffett appeared on Wednesday on CNBC four days after releasing his annual letter to Berkshire Hathaway shareholders.

The CEO says most of the businesses Berkshire owns, except the ones that make housing-related products, continue to inch along and improve.

And he’s optimistic about the future because of the strength of the US system.

He says he doesn’t think the US economy needs as much monetary or fiscal stimulus as it is getting from the Federal Reserve and government spending.

Berkshire owns roughly 80 subsidiaries, including clothing, furniture, jewelry and corporate jet firms. It also has major investments in such companies as Coca-Cola and Wells Fargo & Co.