MKS Instruments is trading at $269.90, down 4.09%, amid broader equity weakness and rising Treasury yields. - No clear company-specific announcement explaining the October 7 decline surfaced in available coverage; weakness in technology and semiconductor shares was consistent with the move. - Rising oil prices and caution ahead of the Federal Reserve minutes also weighed on sentiment. The Dow fell 0.80%, while the S&P 500 and Nasdaq were also lower.