(Bloomberg) — After rebounding Friday to nearly erase a brutal mid-week slide, US stocks are facing more selling this week from trend-following algorithmic funds, according to Goldman Sachs Group Inc.’s trading desk. The S&P 500 Index (^GSPC) has already breached its short-term trigger that prompted Commodity Trading Advisers, or CTAs, to sell stocks. Goldman expects these systematic strategies — which follow the stock market direction rather than fundamental factors — to remain net sellers over the comin ...