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About our company

Navesink International is the premier expert witness firm for financial markets. We help the most prominent law firms win complex cases by providing expert witnesses with the highest quality and the strongest technical knowledge.

Our experts are all industry veterans who can cover the most complex topics and cases in the securities industry. All our experts are selected based on peer recommendations and vetted before representing Navesink International. We take pride in representing the highest quality expert witnesses with the strongest technical knowledge and we do not employ consultants or junior expert witnesses.


We’ve turned to Navesink on multiple occasions and their analyses were accurate, thorough, and withstood rigorous scrutiny by our colleagues and adversaries.
Great interview, really enjoyed this discussion, especially haven read or heard about AIMCo and so many loud whispers about some of the driving factors behind the selloff. It is a gift to be able to make a complicated topic accessible to a broad audience without dumbing it down. As a lawyer, I totally understand why Mr. Quillacq, in addition to his knowledge and experience, makes a perfect expert witness. Mr. Green outdoes himself in this interview, demonstrating deep knowledge and enabling the audience to access this great conversation.
Slugging away on our motion for summary judgment, which is due today, and saved the best for last: plugging in your numbers. Really refreshing to go back through your work and find how clear and comprehensive it is. Thank you both!!!
Wow! You were absolutely fantastic. It is obvious that you are no stranger to this material, and you absolutely nailed your testimony. We very much so appreciate your flexibility, willingness to work within the last second changes of which there were so many, and most importantly, your fantastic report and testimony. Jennifer—you missed an absolutely dominating performance by Gontran.It was an honor to work with you all, and we will certainly keep you in mind should we have a similar need in the future. While I do not wish litigation on our clients, you can rest assured we will return to you should we need expert services in this realm. Jennifer, I will keep Bates group in mind for referrals should we need expert services outside of options—For options, I only want Gontran!
I am an attorney who has worked on FINRA and SEC matters for more than 20 years. In the course of my practice, I have retained Gontran in matters related to futures and options trading. His reports have been thorough, well-researched, well-written, and, most importantly, perfectly accurate. He has my highest possible recommendation as an expert in futures and options trading.
I cannot say enough good things about Luc. He was excellent and a pleasure to work with.

Gontran de Quillacq

Founder & CEO

Gontran de Quillacq is the CEO and Founder of Navesink International, the premier expert witness firm for financial markets. He is an industry veteran, with a background in quantitative research, derivatives trading, portfolio management and hedge fund business development, across both Europe and the US.

Following a successful personal case and testimony, attorneys asked Mr. de Quillacq to explain technical issues and write formal opinions. His activity as an expert witness and consultant grew, leading to Navesink International’s focus on expert witnessing and legal consulting services.

Thanks to his extended industry network and respectful reputation, the firm was able to bring in additional experts of the highest caliber and answer client requests of growing importance and technicity.

To this day, Navesink International still doesn’t plan its future with sales & volume projections, but with exceptional experts, quality of work, and customer satisfaction.