The current losses in long-maturity debt more than double the next biggest slump in 1981, when then Fed Chair Paul Volcker’s campaign to break the back of inflation drove 10-year yields to almost 16%. It also surpassed the 39% average loss in seven US equity bear markets since 1970, including last year’s 25% slump in the S&P 500 when the Fed started to lift rates from near zero.