Scott Rubner, strategist at Goldman Sachs Group, said there was no other way for the S & P 500 to go down at this level. "I don't buy on dips," he warned. Citing data going back to 1928, the managing director of Goldman Sachs' global markets division said that was because this Wednesday, July 17, was historically the turning point for stock market returns, and then the following August is usually the month with the heaviest outflows from passive stocks and mutual funds. Unfavorable seasonality, overpositioning and all the good news that has been absorbed by the market have all put the S & P 500 on the brink of a summer correction. This is also the view that Goldman's trading desk has been leaning towards since at least early June. "From here, the pain trade is no longer up," Mr. Rubner wrote in a note to clients on Wednesday.