In premarket trading, Coherent fell about 4%, Cerebras dropped about 17%, and Cisco declined about 4%.

Before the US stock market opens, "optical communications giant" Coherent has dropped about 4%, despite the company's performance and guidance significantly exceeding market expectations. The short-term profit-taking pressure has led to selling pressure on the stock. AI chip company Cerebras has fallen about 17%, as the company unexpectedly saw a decline in hardware revenue in the second quarter, facing demand fluctuations on its path to "challenge Nvidia." Cisco has declined about 4%, with the company's last quarter revenue hitting a record high and a surge in AI orders, but the full-year AI revenue forecast has disappointed the market.