U.S. bond yields post biggest jump in a generation as global rout rattles investors

The scale of the move is notable. Yields in the global bond market have risen with startling speed over the past few months, and the more than $30 trillion market for U.S. government debt has not been immune. The result is the largest jump in U.S. bond yields in a generation, a shift that ripples through nearly every other asset class.

For investors, the mechanics matter more than the headlines. Bond yields and prices move in opposite directions, so rapid yield increases mean falling prices for existing bonds — including the safe-haven Treasurys many portfolios hold for stability. Higher yields also reset the reference point for valuing stocks, since future corporate earnings are discounted at prevailing rates.

What to watch: whether the pace of the rise settles or continues, how other markets respond, and whether the move reflects changing growth and inflation expectations or mainly shifts in supply and demand for government debt. Speed, as much as direction, is what has rattled investors.