Founder and CEO of Droit - the firm that turns the living text of financial regulation into logic a machine can defend, line by line.
Every trade a big bank makes carries a hidden legal question - can I do this, here, with this counterparty, under which set of rules? For decades the answer lived in binders, memos and the heads of compliance officers. Brock Arnason decided the answer should live in code.
That decision became Droit, the New York company Arnason founded in 2012 and still runs as CEO. Its premise sounds almost too clean: take the actual text of a regulation, annotate it, and compile it into a model that spits out auditable decisions. Droit calls the discipline computational law. Goldman Sachs, Wells Fargo and UBS call it the thing that now sits between their traders and the rulebook.
In 2025 the capital-markets technology company FIS - which serves more than 20,000 clients worldwide - acquired Droit and announced plans to put its engine at the heart of a global compliance and post-trade platform. The small firm that started by untangling Dodd-Frank had become infrastructure.
"We're trying to get people to buy into a vision of treating the law as data, and to subscribe to a data service that defines the best-practice, consensus interpretation of the law."
Before Droit, Arnason was an Executive Director of Fixed Income E-Commerce at Morgan Stanley. He ran Matrix, the bank's client trading portal, and he steered the firm's strategy for swap execution facilities and its Dodd-Frank compliance programs. When the 2008 crisis triggered a wave of new derivatives rules - clearing mandates, business-conduct standards, electronic-trading requirements, price transparency - he watched the industry try to absorb it all by hand.
The rules kept changing. The interpretations multiplied. A single transaction could touch several jurisdictions at once, each with its own evolving text. Arnason's read was that this was not a staffing problem to be solved with more analysts. It was a data problem. So in 2012 he left to build the thing that could keep pace.
His training helped. Arnason holds an M.Eng. and B.Sc. in Engineering Physics from Cornell University and an MBA from the University of Chicago - a combination of someone comfortable modeling messy systems and comfortable selling the model to a boardroom.
"Financial institutions are under pressure to adhere to increasing and ever-changing regulatory requirements, often in multiple jurisdictions for a single transaction."
Droit's patented approach treats a regulation less like prose and more like source code. Here is the loop, simplified.
Monitor the live source documents - the actual statutes, rules and guidance, as they change.
Annotate the text and compile it into a transparent logic model tied back to each underlying line.
Run a trade through it: pre-trade "can I?" controls, then transaction and listed-derivatives reporting.
Every decision is auditable and attributed to the annotations that produced it - no black box.
Droit pairs old-school symbolic logic with large language models, including a "decision decoder" that explains each regulatory path in plain language while keeping the audit trail intact.
Rather than each bank interpreting the rules alone, Droit builds a shared, best-practice reading agreed across top sell-side and buy-side firms - the law as a subscription.
What began with U.S. OTC derivatives rules now spans EMIR and other regimes, covering nearly every asset class across jurisdictions.
Droit holds ISO/IEC 27001 and ISO/IEC 27017 certifications - the kind of credential that lets a global bank put your engine in its trade flow.
"What makes us unique is our approach to computational law. We have patented technology that allows us to monitor digital text, sources of the law, create logic models on that text and then take decisions that are auditable, transparent and attributed to the actual underlying annotations on the text."
"FIS have asked us to be more ambitious, so I think that the pace will accelerate."
For most of its life Droit was the specialist - the firm a bank called when the rulebook got complicated. The FIS acquisition flips that. Instead of bolting onto someone else's workflow, Droit's computational-law engine becomes part of the core, available across FIS's enormous client base of banks and asset managers.
Arnason frames the prize as consistency. The same regulatory logic that says "yes, you can trade this" before a trade should be the same logic that reports it afterward. Apply one engine across the whole trade lifecycle - pre-trade controls through post-trade reporting - and the gaps where interpretations drift start to close. He has said FIS wants Droit to be more ambitious, and that the pace will pick up accordingly.
The frontier keeps moving, too. Droit's coverage now reaches into newer corners of the market - digital assets, even prediction markets - where the rules are still being written. Which is, in a way, the whole point: a company built to keep up with regulation that never sits still.
Led by Goldman Sachs and Wells Fargo, with Pivot Investment Partners and trading firm DRW.
March 2023. Led by Pivot Investment Partners and UBS Next, with Goldman Sachs returning.