Jason Evans knew he had to act fast. It was 8:30 in the morning on Aug. 1, which meant the U.S. Labor Department’s monthly wage data had just been released. One day earlier, the 46-year-old co-founder of NineAlpha Capital LP, a hedge fund specializing in U.S. government debt, detected signs of bearishness in the bond market after a report showed employment costs rose by the most since 2008. So when his computer screen showed hourly earnings were unchanged in July, he knew exactly what to do: direct his traders to buy more Treasuries.