[U.S. Stock Market Pre-Market: Memory Chip Stocks Mostly Down, SK Hynix Drops About 5%] According to Golden Finance, on October 13, in the U.S. stock market pre-market, memory chip stocks mostly declined, with SK Hynix down about 5%, Western Digital down about 4%, SanDisk down about 4%, Micron Technology down about 3%, and Seagate Technology down about 3%.