NEW YORK — U.S. stocks spent a second day flipping between small gains and losses Thursday as investors again looked for hints about the Trump administration’s stance on international trade and the dollar. Airlines plunged again while biotech drugmakers climbed.

On Thursday:

The Standard & Poor’s 500 index gained 1.71 points, or 0.1 percent, to 2,839.25.

The Dow Jones industrial average climbed 140.67 points, or 0.5 percent, to 26,392.79.

The Nasdaq composite slipped 3.89 points to 7,411.16.

The Russell 2000 index of smaller-company stocks added 2.06 points, or 0.1 percent, to 1,601.67.

For the week:

The S&P 500 is up 28.95 points, or 1 percent.

The Dow is up 321.07 points, or 1.2 percent.

The Nasdaq is up 74.79 points, or 1 percent.

The Russell 2000 is up 4.04 points, or 0.3 percent.

For the year:

The S&P 500 is up 165.64 points, or 6.2 percent.

The Dow is up 1,673.57 points, or 6.8 percent.

The Nasdaq is up 507.77 points, or 7.4 percent.

The Russell 2000 is up 66.16 points, or 4.3 percent.