Key Takeaways UnitedHealth shares will likely remain under the microscope on Monday after logging their worst daily decline since 1998 as the healthcare giant cut its full-year profit forecast amid rising medical costsA recent recovery in the stock toward its record high ended abruptly last week,

Shares of UnitedHealth took a historic tumble Thursday after the U.S.’ largest health insurer fell far short of Wall Street’s estimates in its quarterly earnings report, dragging down the blue chip Dow Jones Industrial Average with it.

A steep slide in UnitedHealth Group shares was dragging on the Dow Jones Industrial Average on Thursday, putting the blue-chip index on track for historical underperformance versus the S&P 500.