Homebuyers may not see significantly lower mortgage rates this year, but other parts of the housing market show promise.

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.

Fact checked by Vikki VelasquezWarren Buffett’s Berkshire Hathaway Inc. (BRK.A, BRK.B) is the single largest private holder of U.S. Treasury bills, surpassing even the Federal Reserve’s own holdings.