Dow Movers: MSFT, MRK

In early trading on Thursday, shares of Merck topped the list of the day's best performing Dow Jones Industrial Average components, trading up 3.9%.

Year to date, Merck registers a 8.5% gain.

In early trading on Thursday, shares of Merck topped the list of the day's best performing Dow Jones Industrial Average components, trading up 3.9%.

Year to date, Merck registers a 8.5% gain.

And the worst performing Dow component thus far on the day is Microsoft, trading down 0.5%.

Microsoft is showing a gain of 44.6% looking at the year to date performance.

Two other components making moves today are Salesforce.

Om, trading down 0.4%, and Caterpillar, trading up 2.6% on the day.