JPMorgan strategists have warned that the S&P 500's recent rally may lose momentum in the coming months due to a combination of higher prices and weaker economic growth in the United States over the summer. The bank highlighted the risk of a stagflationary episode, characterized by stagnant growth and inflationary pressures, which could threaten US stock market performance. Additionally, JPMorgan pointed to ongoing trade tensions as another factor that could weigh on market gains. The S&P 500 has been underperforming compared to European indices amid these headwinds. Investors are advised to monitor these risks closely as they could impact the trajectory of the US equity market.