Investors flocked in droves to the safety of Treasurys on Monday in a manner not seen since the days that followed the 1987 stock-market crash, after the sudden closure of two banks and banking regulators stepping in over the weekend to fully protect their deposits.
The policy-sensitive 2-year Treasury yield BX:TMUBMUSD02Y briefly fell below 4% earlier Monday and headed for its biggest three-day decline since Oct. 22, 1987 — an infamous period that was kicked off by “Black Monday,” when Dow industrials dropped 22.6% on Oct….


