Key Takeaways Shares in Zscaler plunged in extended trading Tuesday after the provider of cloud-based cybersecurity services issued earnings guidance that came in significantly below analysts' expectations. Two rallies in the stock up to the 200-day MA in July and August have been met with considerable resistance, indicating underlying selling pressure. Amid earnings-driven weakness, investors should monitor key chart levels at $164, $143, and $135. Shares in Zscaler (ZS) plunged in extended trading Tuesday ...