UnitedHealth, Merck share losses lead Dow's 183-point drop

Shares of UnitedHealth and Merck are trading lower Thursday afternoon, dragging the Dow Jones Industrial Average into negative territory. The Dow
DJIA,
-0.63%

was most recently trading 183 points (0.5%) lower, as shares of UnitedHealth
UNH,
-5.70%

and Merck
MRK,
-3.63%

are contributing to the index’s intraday decline. UnitedHealth’s shares are down $29.97, or 6.0%, while those of Merck are off $3.98 (3.7%), combining for a roughly 224-point drag on the Dow. Travelers
TRV,
-2.73%
,
Chevron
CVX,
-1.85%
,
and Caterpillar
CAT,
-2.41%

are also contributing significantly to the decline. A $1 move in any one of the 30 components of the benchmark results in a 6.59-point swing.