It was a rough day in the stock market as a selloff in South Korea left that market down 9.9% and raised concerns about the ongoing mania in chip stocks, particularly memory names.Much of the intense panic concentrated on Micron (MU), which cratered more than 13% today. This massive pre-earnings flush comes just 24 hours before they report their fiscal Q3 earnings on Wednesday. Despite a major multi-year AI supply deal announced yesterday with Anthropic, options markets are pricing in a massive 17% post-earnings swing, prompting investors to aggressively de-risk.The move certainly spread to chip stocks more broadly and the red-hot SOXX chip was down 7.9%. At the bottom of the article are the main components of the chip index and how they did today.As for broader stocks, it was more mixed than it looks from the aggregate numbers as IBM, telecom names and consumer staples strengthened alongside a 2% climb in Microsoft and 1% in Amazon. The advancers led the decliners in the S&P 100.Notably, the Nasdaq also held its opening lows despite skirting along them a handful of times.Closing changes:S&P 500 down 1.4%Nasdaq Comp -2.2%Russell 2000 -0.9%DJIA flatToronto TSX Comp -0.3% This article was written by Adam Button at investinglive.com.