US benchmark equity indexes are on track to close mixed on Monday, after investors parsed a Moody's downgrade of the US government's credit ratings and comments by a Federal Reserve official.

The Dow Jones Industrial Average gained 0.2% to 52,718.11, while the Nasdaq Composite decreased 0.2% to 19,165.45. The S&P 500 was down 0.1% to 5,950.46. Among sectors, healthcare posted the largest gain while energy saw the steepest decline.

UnitedHealth Group (UNH) shares surged 7.2%, the top gainer on the S&P 500 and the Dow.

Dollar General (DG) shares were up 4.7%. Goldman Sachs and Morgan Stanley raised the price target on the company's stock to $96 from $85, and to $85 from $80, respectively.

First Solar (FSLR) was the worst performer on the S&P 500, down 8.9%. Goldman Sachs raised its price target on the company's stock to $255 from $204, while Barclays increased it to $222 from $204.

The 10-year US Treasury yield was down 2.2 basis points to 4.46%, while the two-year rate was down 3.7 basis points to 3.97%.

June West Texas Intermediate crude oil was flat at $61.98 a barrel.