Practical Pointers for Expert Witness Testimony in an Antitrust Trial

Expert witnesses are central players in an antitrust case. As a result, it is critical for counsel to set them up for success at every stage-from selection through trial testimony.

In a new article published in the ABA's Antitrust Magazine (Spring 2026), Orrick partner and head of antitrust litigation Eric Hochstadt and associates Allen Davis and Anne Corbett offer practical guidance on how to maximize the impact of economic expert testimony.

KEY TAKEAWAYS

1. Pick your expert with trial in mind. Evaluate credentials, demeanor, and jury appeal-not just technical skill-and watch out for bias risks that could undermine credibility, such as a history of testifying for the same party or publicly advocating for a position before being retained.
2. Write expert reports for a generalist audience. Expert reports are not academic papers or legal briefs; they should be persuasive and accessible for the court in evaluating summary judgment. They also must include every topic, figure, and demonstrative the expert may use at trial.
3. Target FRE 702 challenges at foundations, not conclusions. Effective pre-trial challenges under the amended FRE 702 focus on gaps in qualifications, factual foundation, methodology, and objectivity-not issues that go to the weight of an expert's opinion for resolution by the jury.
4. Keep direct examination short and clear. Lengthy expert testimony risks losing the fact-finder. Prioritize brevity, use plain language, and structure testimony around the most critical opinions that will have a lasting and memorable impact.
5. Focus cross-examination on what was left unsaid. Rather than rehashing the opposing expert's direct testimony, effective cross-examination targets bias, methodological gaps, areas the expert did not investigate, extreme or radical opinions, and any post-discovery public statements that bear on credibility.