Cybersecurity stocks are up 24% this year, nearly five times the gains of the S&P 500.
Cisco's shares previously fell about 3% after a report said Amazon planned to sell a competing product at a cheaper price.
Cisco Systems stock has rallied more than 35% since November 2017 and could gain additional ground after Wednesday's earnings report.
Discover how Cisco became one of the greatest IPOs in history during the 1990s and how it continues to innovate and move forward today.
But Goldman Sachs' chief US equity strategist sees danger for Facebook and its ilk.
Corporate outlays on stock buybacks will rise by more than 50% in 2018, boosting share prices.
Arista faces new competition from makers of white-box switches, while its main rival Cisco becomes more aggressive on equipment pricing.
Legacy tech titans lead the 30-company index amid a larger market meltdown.
Analysts expect the stock to gain another 25% on tax benefits and strong end markets.
As interest rates rise, investors worry the end of the bull market is nigh, but some stocks do well when rates rise.