Teradyne is trading 4.47% lower at $309.22 after investors focused on fourth-quarter guidance and the prospect of a sequential step-down. - Third-quarter revenue of $1.306 billion and non-GAAP EPS of $2.29 beat expectations. - Fourth-quarter revenue guidance is $1.25 billion–$1.35 billion; results were released after the October 27 regular session. - Teradyne closed October 27 at $323.68, up 4.75%, before the pre-market pullback; its earnings call is scheduled for October 28 at 8:30 a.m. ET.