Red-hot inflation also hit Verizon Communications Inc VZ.N, which fell 4.2% after cutting its annual adjusted profit forecast. Seagate Technology Holdings STX.O plunged 11% after the memory chip maker announced plans to cut production, hurting shares of rivals Micron Technology MU.O and Western Digital WDC.O. By Shreyashi Sanyal July 22 (Reuters) - The S&P 500 and the Nasdaq headed for a lower open on Friday as social media and ad tech firms led declines after dismal quarterly revenues from Twitter and Snap, while an upbeat forecast from American Express looked set to boost the Dow.