Fears that the artificial intelligence (AI) investment cycle may be nearing its peak triggered a wave of panic selling in semiconductor stocks, Friday, sending shares of Korea’s two chipmaking giants, Samsung Electronics and SK hynix, plunging nearly 10 percent. As of 9:30 a.m., SK hynix had tumbled 11.71 percent, while Samsung Electronics had fallen 9.98 percent. The benchmark KOSPI opened 2.24 percent lower at 5,263.26 before triggering a circuit breaker just three minutes into trading, which temporarily suspends program trading for five minutes when market movements become too volatile and breach a certain threshold. The index subsequently plunged more than 8 percent at one point in morning trading, falling below the 5,000 mark for the first time in 10 months since January.