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.

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.

NEW YORK (AP) — U.S. stocks drifted to a mixed finish on Thursday as President Donald Trump’s tariffs taking effect on dozens of countries had only a muted effect on markets worldwide.