Pacific Biosciences is trading 7.4% down at $1.81, alongside weakness across the biotech sector. - Biotech ETF XBI is down 2.06% during the regular session. - Major indexes are mixed: the Nasdaq is down 0.58%, while the S&P 500 and Dow are slightly higher. - No clear company-specific catalyst was found for October 16; PacBio’s latest listed press release announced its November 4 earnings report date, not a new operating or financial development.