Shares of Acacia Communications Inc. plunged 23% in Monday morning trading after the U.S. banned American companies from selling components to China-based ZTE Corp for seven years. ZTE pleaded guilty to conspiring to violate U.S. sanctions by shipping goods to Iran, according to Reuters, which reported on the ban this morning. ZTE accounted for 30% of Acacia’s revenue in 2017, according to the company’s most recent annual filing. Shares of other optical names are down as well in Monday’s session, including Lumentum Holdings Inc. , off 10%, Finisar Corp. , off 4.4%, and II-VI Inc. , off 2.5%. Acacia’s stock is down 50% over the past 12 months, while the S&P 500 is up 50% in that time.