A maker of benchtop instruments that read the sequence of proteins one molecule at a time, using semiconductor chips to detect individual amino acids. Its Platinum and Platinum Pro machines, sold to research labs, aim to make protein analysis cheaper and more automated than mass spectrometry. Founded in 2013 by Dr. Jonathan Rothberg, who earlier pioneered next-generation DNA sequencing, the name blends 'quantum' (its single-molecule detection) with 'Si,' the chemical symbol for silicon, the material of its chips.
Select a row to see that insider’s individual transactions. † Sum of the holdings confirmed in the 12 months before this insider's last filing. A Form 4 reports a holding per line — held directly, or through a named trust, partnership or foundation, and in each share class separately — never a person’s total. Lines not restated in that time are left out and shown apart: an active filer restates what they still hold, so a line they did not restate is more often an entity since renamed, whose shares a successor line reports too. An amber marker means some were left out.
Net open-market activity over the last 5 years: -3.47M shares. Grants, option exercises and tax withholding are excluded — they are compensation mechanics, not decisions to buy or sell.