Ralph Lauren Corp RL.N dropped 3.5% after it forecast full-year sales below analysts' estimates. Leading losses among the 30 blue-chip Dow components in premarket trading was Cisco Systems Inc CSCO.O, down 5.4%, after the network gear maker cautioned that supply chain issues will linger through the end of 2021 and forecast its current-quarter profit below estimates. "Unprecedented stimulus, supply chain imbalances, and prospects for a record tight U.S. labor market are creating high uncertainty about the inflation outlook," said Linda Duessel, senior strategist at Federated Hermes.