Fighting a turkey hangover is no joke. The struggle is real. But Wachtell, Lipton, Rosen & Katz; Davis Polk & Wardwell; Simpson Thacher & Bartlett; and Sullivan & Cromwell seem to have hit the ground running, announcing a $44 billion all-stock merger Monday between S&P Global and IHS Markit that will combine the two largest providers of financial data to Wall Street. 

By deal value, the merger is the largest of the year thus far.