Market Sentiment - The recent record run by the US stock market is at risk as investors are retreating from their strong bullish positioning [1] - Evidence of buyers' fatigue is suggested by weak flows into US equity funds compared to earlier in the year, although they have returned to positive territory [2][3] Investor Behavior - Flows from American and European investors into US and non-US domiciled equity funds have been soft, while global flows excluding the US have shown positive but deteriorating trends [2] - Retail flows into US equity funds have recently faltered, with passive flow from retail investors turning negative [4] Valuation and Positioning - Elevated equity valuations, a decline in bullish sentiment, and seasonal weakness are concerns for the market, particularly with September historically being the worst month for S&P 500 returns [4] - A measure of aggregate equity positioning by Deutsche Bank has slipped but remains modestly above neutral, with professional portfolio managers now moderately underweight [5] Market Reactions - US stocks saw a slight increase following a dip from a weaker-than-expected jobs report, with the S&P 500 rising 0.2% [6] - The options market indicates concerns about the rally, as the five-day moving average of total net volume in call options fell last week, driven by a drop in single stock contracts [7]