Investors had a delayed reaction to Friday's jobs report which shored up a December rate hike. The realization the Federal Reserve might move off of crises-level rates by year's end hit stocks hard. The Dow erased all year-to-date gains. Norfolk Southern (NSC) spiked on reports Canadian Pacific Railway (CP) is interested in a merger. The second-biggest railroad company in Canada has reportedly already held early talks with its U.S. industry peer. Mallinckrodt (MNK) shares plummeted after short seller Citron Research dragged the drugmaker into the Valeant Pharmaceuticals (VRX) scandal. The short seller previously alleged Valeant had committed accounting fraud through its Philidor subsidiary and today said Mallinckrodt was a 'far worse offender,' of the same alleged scam.