Matthew Armstrong

Director, Practice Area Development


  • Silicon Valley


Matt Armstrong manages development initiatives for the Cornerstone Research’s practice areas related to finance, financial institutions, and securities. In his more than ten years with the firm, Mr. Armstrong has developed expertise analyzing issues related to market efficiency, class certification, loss causation, and damages in numerous Rule 10b-5 and Section 11 cases.

Mr. Armstrong’s analyses in these matters have included:

  • Examining the impact of information on securities prices
  • Evaluating whether investor losses were the result of alleged misstatements and omissions
  • Determining per-share inflation and class-wide damages

Mr. Armstrong conducts analyses on matters involving large and complex datasets. In particular, he has estimated damages arising from market timing in mutual funds and consulted to the Financial Industry Regulatory Authority (FINRA) to assess the impact of a proposed rule change in the over-the-counter equity markets. Mr. Armstrong has also addressed issues related to options trading at the class certification stage.

Mr. Armstrong works with counsel to support the preparation of expert reports and deposition testimony, assesses opposing experts’ analyses, and provides expertise across all phases of litigation, including mediation and trial.