Stock Market Down 800 Points in Worst Fourth Quarter Opening Since World Derivatives Panic of 2008; Manufacturing Slows, Confirming Economic Contraction; Market Downdrafted as U.S. Stock Buybacks Decline After Record $1 Trillion Pace in 2018; New York Fed’s Emergency Liquidity Injections To Prop Up Repo Money Market Already Approaching $1 Trillion; New York City Residential Real Estate Market in Free Fall