WALL Street stocks opened higher yesterday on very light trading. After the first hour's trading the Dow Jones average of 30 industrial stocks was up 26.77 to 4,607.39. Advancing issues led decliners by about 3:2 on the New York Stock Exchange, where volume came to 33.79 million shares in the first half hour, down from Thursday. The NYSE composite index gained 0.83 to 300.18, while the Standard and Poor's 500 index was up 1.61 to 559.07. The NASDAQ composite was up 1.26 to 1,022.19 while the American Stock Exchange's market value index was up 1.31 to 530.24. There was good news on the US economy on Friday morning. Sales of previously owned homes rose a swift five per cent in July to the highest level in more than a year. The home sales report didn't dent bond prices as could have been expected. Bonds tend to fall on signs of a growing economy because of the threat of inflation and that sometimes pressures stocks because when bond prices fall, interest rates rise, boosting borrowing costs for corporations.