Legally a sale, economically a secured loan: a bond is handed over for overnight or few-day cash and bought back at a set price. It is the main plumbing through which banks and central banks square up their daily cash, and a spike in repo rates reads as a warning that cash is drying up somewhere.
Awaiting gradingOn July 31 the New York Fed sold euros to buy yenScore on the Fed's H.4.1 released August 6 (as of August 5): dollars borrowed by foreign monetary authorities against Treasuries moving off zero counts as the FIMA route opening, staying at zero counts as the original expectation missing.