I’ll have more complete analysis — with graphics — in a few minutes, but Moody’s announcement of a ratings review should be completely shrugged off.
Merck remains A1/P1, and is an extremely safe credit risk — in the corporate space.
That is to say Merck is high investment grade, and would need to fall six notches to be in any danger. Moody’s won’t drop it more than one notch, and S&P will hold Merck stable.
Net, net — a non-event. Table of rating grades at right in a moment, but for its size., Merck carries very very little leverage risk.
Here endeth my sermon.