Arista Networks Inc (NYSE:ANET) stock is down 5.8% at $405.83 at last glance, despite the company's better-than-expected third-quarter results -- including an earnings beat and record revenue -- due to shrinking margins. The computer networking firm also announced a four-for-one stock split, effective Dec. 3, and upbeat current-quarter guidance. Today's price movement could also be a slight correction after the stock's recent rally, which culminated in a record high of $431.97 last session. Year to date, th ...