Merck&Co Stock fell by 4.60% to trade at $84.32 by 09:30 (14:30 GMT) on Wednesday on the NYSE exchange.
The volume of Merck&Co shares traded since the start of the session was 1.12M. Merck&Co has traded in a range of $84.17 to $84.90 on the day.
The stock has traded at $89.1800 at its highest and $84.3200 at its lowest during the past seven days.
