In true UnitedHealth fashion, the big health insurance stock was denying the Dow of a daily gain on Tuesday.

The Dow was down 160 points, or 0.4%, but UnitedHealth stock was shaving 382 points off the index on its own with a nearly 17% drop.

UnitedHealth is regularly a thorn in the Dow’s side due to the index’s antiquated weighting by stock price rather than market cap. UnitedHealth has had a stock price north of $600 this year, meaning it was at one point the index’s most important stock.