Repo is Wall Street's big year-end worry. Why?

Repurchase agreement (repo) is one of the main drivers of US financial System. Interest rates in U.S. money markets increased to 10% for some overnight loans, while the US benchmark overnight rate is currently set in a range of 1.5% to 1.75%. A reduction in US bank reserves held at the US Central bank is a large contributor to the repo strain experienced because it can be made available for loan.
Reuters