Wall Street has its eyes set on the AI trade, which has led the market. Data analytics firm Palantir ( PLTR) saw its market cap balloon past $420 billion this week after posting a boom in revenue and contracts.

US stocks retreated on Tuesday as investors digested the latest wave of corporate earnings, economic data, and various tariff updates. Palantir (PLTR) stock jumped roughly 7% after the company's earnings report beat expectations and revealed its revenue had topped $1 billion in a quarter for the first time.

Warren Buffett is telling investors something -- not through what he has said, but through his actions with the balance sheet of his investment conglomerate Berkshire Hathaway ( BRK.A -0.40%) ( BRK.B 0.83%). These actions should be taken as a warning sign with the stock market reaching elevated valuation levels in recent months.