By Saqib Iqbal AhmedNEW YORK (Reuters) -Wall Street is set to close one of its calmest quarters in nearly six years, and the lull after a volatile start to 2025 has many market participants increasingly alert for renewed market gyrations. For the third quarter, the S&P 500's one-month…This story appeared on finance.yahoo.com , 2025-09-30 10:03:08.