US stocks are closing out a rough quarter on a positive note. Major indexes rallied on Wednesday, but the market still ended the third quarter with its worst loss in four years. All five of the biggest drops in the year occurred in the last three months as traders worried about slowing growth in China and uncertainty over US interest rate policy. The Dow Jones industrial average gained 235 points, or 1.5%, to 16,284. The Standard & Poor's 500 index jumped 35 points, or 1.9%, to 1,920. The Nasdaq composite climbed 102 points, or 2.3%, to 4,620. (More US economy stories.)