UnitedHealth Group’s grip on the Dow has weakened, but the health insurance stock still managed to buoy the index on Wednesday.

With UnitedHealth up 2.3%, it was one of only five Dow stocks rising on the day. With the Dow down 150 points, or 0.4%, UnitedHealth was adding 41.7 points to the index on its own.

The Dow only includes 30 companies and measures its members by their stock price rather than market cap. That means firms with high stock prices can have a greater impact than far bigger companies that sport slimmer stock prices.