The US-Iran deal is not a market mover in the usual sense. It is a rotation. Two premiums that had been pricing the same war collapsed at once — the energy premium embedded in crude and the geopolitical risk premium embedded in equities — and they unwound in the same session. For everything except one sector, the two forces pulled in the same direction, and the result was one of the sharpest risk-on moves of the year.

For decades, U.S. Treasury securities commanded a pricing premium that economists call the convenience yield — the extra return investors were willing to forgo in exchange for holding the world’s most liquid, safest, most universally accepted collateral. That premium is eroding. The GAO’s March 2026 federal debt management report (GAO-26-107529) treats this as a structural shift, not a market fluctuation, and the data support that reading. The convenience yield is not directly observable.