October 13, 2026Main stage4 min read

A Hedge Fund as a Function

Frank Long models an investment firm as a function that turns external and internal context into selection, size, and timing. The engineering challenge appears when that function is decomposed into work that code, models, and people can each perform well.

Frank LongCoatueHead of AI

From the conference livestream · 6:47:46–7:01:37 on YouTube. The player starts and stops at this session’s boundaries.

6:47:47 ↗

Compress the world into an investment decision

An investment firm takes in an enormous amount of information and produces a small decision: which asset, how much, and when. Frank Long uses that compression problem to explain the AI work at Coatue.

The function takes external and internal context and returns three values: selection, size, and timing. Repeated decisions build the portfolio. Writing that down gives engineers a starting point; decomposing the function reveals how much work it contains.

The first requirement is access. Long argues that information employees can see on their screens should also be available to the firm’s agents through APIs. Hiring an exceptional investor but withholding most of the service logins would waste that person’s abilities; an agent without access has a similar limitation.

External context includes news, prices, and filings. Internal context includes current positions, liquidity and risk constraints, earlier research, and experience with a company or management team. Long emphasizes that this is a cultural accomplishment as well as a technical one. Notes about decisions taken, decisions avoided, and outcomes become useful inputs only if the organization has made a habit of preserving them.

6:50:57 ↗

Even gathering the news is a collection of decisions

Putting all that information into a context window does not produce a trustworthy investment decision automatically. Long first decomposes the function into gathering relevant information, analyzing it to form a view, and turning that view into a decision. Each step has an input and an output the next step can use.

Then he zooms into one small part of gathering: interpreting Korean-language news about semiconductors and AI. A team that does not speak Korean has an obvious reason to use models, but translation is only one piece of the system.

Articles need to be collected through some interface: a licensed feed, a CLI, or an MCP connection. The input design has choices of its own. How should the articles be chunked? Should images reach the model as images or be converted to text? These choices affect which information survives into the later stages.

The system also has to filter relevance. A Korean news source can carry sports stories alongside semiconductor coverage. After filtration come more choices: translate, summarize, extract structured data, or combine those operations. Finally, the new information needs to be checked against internal notes, prior views, and meeting records before updating the firm’s understanding.

Long treats these implementation choices as hyperparameters: settings to compare against the quality of the resulting research.

6:55:06 ↗

Choose the runner for each piece of work

A function can be performed by different kinds of runner. If the question is whether a price-to-earnings ratio is below fifteen, an ordinary comparison is fast, cheap, and dependable. Classical statistics or machine learning can capture relationships more complex than an explicit rule.

Language models become useful for tasks such as summarization, where a collection of hand-written conditions would be a poor substitute. People remain important runners too. Meeting a management team calls for judgment and real-world interaction; Long jokes that he would not send an if statement to the meeting.

The aim is to maximize the quality of each part of the process. Replacing a person or a deterministic step with an LLM has no independent value if the resulting work is worse.

This also means the architecture will rarely be a simple chain. The news workflow can branch: one route extracts quotations and checks their sources; another extracts figures and relates them to the drivers of a stock; another tests the new evidence against an existing view.

Coatue’s news-gathering diagram branches through filtering, translation, quote and figure extraction, source checks, internal comparisons, proposal, and review.

The slide at 6:57:31 makes the alternatives and feedback paths visible. Source checking can send work back when a quotation does not match. Review can revise a proposal. Internal notes join the workflow at several points rather than appearing only in one initial prompt.

6:58:01 ↗

Find something small enough to evaluate

Even the runner categories combine. Collection may use code; filtering may use a model plus rules; a human may assess portfolio implications with software helping retrieve the relevant evidence. Within the model-based steps, the team can vary model size, reasoning effort, harness, skills, and hooks.

That produces an enormous search space for just one part of one data source. Long’s response is to compartmentalize work into units the team can understand and evaluate. Without a useful objective, changing models and prompts becomes aimless tuning.

An evaluation might show that a small trained model should replace a large LLM, that a rule is sufficient, or that portfolio interpretation should remain with a person. Those are improvements if they produce better results for that step. The architecture needs to make such substitutions possible.

At the scale of an investment firm, many sources and transformations form a much larger graph. Making it comprehensible technically—and something the organization can actually adopt—is the challenge Long leaves with the audience.

The same decomposition could help with policy, drug discovery, or corporate strategy: gather information, interpret it, decide what to do. Each field would need its own tasks and standards. Start with a part small enough to evaluate, then choose the code, model, or person that performs it best.

Full transcript 204 timestamped passages

Machine transcription with reviewed terminology and names. Some recognition errors may remain. Timestamps refer to the livestream; subtitle downloads are timed to the session clips.

6:47:47Hello

6:47:47Exciting to be here. My name is Frank. I work at Coatue which is a technology investment firm across public and private markets

6:47:54So, in our business, what you really need to do is be able to take high conviction bets

6:48:00on big themes and watch those play out.

6:48:03I think, honestly, a career is the same way.

6:48:06And last year when I joined Coatue, the bet that I wanted to make was I think that agents

6:48:11will have an even bigger impact in investing than they did at coding.

6:48:15I know that's a big statement.

6:48:16We're all here because of the transformative impact that AI has had in coding.

6:48:21But I really believe it strongly.

6:48:23And today I want to talk a little bit about the framework that we use to actually realize

6:48:27that impact.

6:48:29So, at a high level, you can think about a hedge fund as a function that takes in two

6:48:34parameters, context external and context internal, and spits out one tuple.

6:48:40Selection, size, timing.

6:48:44stock, how much, when.

6:48:47And I think this is a good framework to actually ground our work, which is we are trying to

6:48:54solve this compression problem of how do you take all the information in the world and

6:48:58spit out this one simple tuple and the product that we provide is essentially a time series

6:49:05of this tuple that constructs a portfolio.

6:49:08let's start from the top, which is the inputs.

6:49:11simple philosophy.

6:49:13We use our screens, we look at stuff, we do work.

6:49:17Every single thing that a human can see in pixels on the screen, an agent in your building

6:49:21should be able to see via API.

6:49:23The analogy I use is imagine you brought the smartest people ever, the greatest investors

6:49:29alive and you brought them into your company but you gave them a computer without logins

6:49:34to 75% of your services.

6:49:36It's almost immaterial how smart this system is if it doesn't have the tools to actually

6:49:41action that.

6:49:42So the two parts, external context, no surprises here, think the news, prices, filings, all

6:49:51of that should be easily accessible and not via dragging and dropping, copy and pasting,

6:49:56like directly via API.

6:49:59Internal context is just as important, right?

6:50:03So this is your own firm situation.

6:50:06So that might be our current positions, potential liquidity and risk requirements we have around

6:50:10certain names, and past case studies or history with a certain sector or stock or management

6:50:19team.

6:50:20That is all super important.

6:50:21So this is the foundation, and I think, no credit to me, Coatue has been an amazing leader

6:50:26on this for over a decade.

6:50:29It is both technological and cultural.

6:50:31We have an amazing data science team, amazing processes, amazing systems that bring all

6:50:36this in, and just as importantly, we have a culture that is super, super rigorous and

6:50:42built from the ground up to capture all this insight.

6:50:45For decades, we filed every single note about every single trade, about every single decision

6:50:50we made or didn't make about what went well and what didn't go well, and that has poised

6:50:54us to expose us to AI.

6:50:57If you think about it, I probably can't just take all of those things, jam them into a

6:51:03context window and get my magic three numbers and go home.

6:51:07It can't be that easy.

6:51:09You probably have to break down this function a bit further.

6:51:14So maybe the first step is I take in that external and internal context and I gather

6:51:20it.

6:51:21I want to gather it, I want to filter out what is relevant and not relevant.

6:51:25Okay, well, I pulled some news articles about the MBA that probably isn't material to stocks,

6:51:30but this is related to local permitting that might impact data centers.

6:51:36There is a lot of nuance in this gather step.

6:51:41you will see probably the next step is I need to analyze that information and form

6:51:44a view.

6:51:46I need to think about what that means for the markets, public and private, and then

6:51:54I need to take that view and turn it into a decision.

6:51:57A decision object has these three parameters, these three sub pieces.

6:52:03You can see every single step has an input and an output, and the input for the subsequent

6:52:10step is the output that the previous function generated.

6:52:14I think as an engineer, this is a way for me to conceptualize the problem in a way that

6:52:20makes a lot of sense.

6:52:21But even this, it really can't be as simple as writing three functions.

6:52:26So let's just, to really appreciate the scope and understand the full complexity of the

6:52:33problem, let's look into the first step, a tiny sub piece of a tiny sub piece of just

6:52:38gathering information and let's do a case study on interpreting the news.

6:52:45So it's probably no secret to you guys that news from Asia and Korean media outlets has

6:52:52been super important this year because semis, AI, have been a huge, huge theme in the market.

6:52:59Huge theme.

6:53:00And I think this is an area where AI is poised to have a lot of impact.

6:53:05Reading Korean language news better than our completely non-Korean speaking staff.

6:53:12I think I have a good thesis that this might be a good use case.

6:53:15So you can imagine the first step is I have articles.

6:53:20I need to collect the articles.

6:53:23This

6:53:23could be an MCP, this could be a CLI, license the data feeds, clean the data feeds. There are a lot of ways to do this and a lot of dimensions of freedom for how you can even just write this simple piece. How do I chunk it when I pass it to the LLM? Do I want to pull the images as images? Do I want to pull the images and then turn the images into text? There are actually a lot of knobs here.

6:53:48I almost think about those knobs as hyperparameters in a traditional machine learning system.

6:53:53I think about each of these knobs as something for me to tune and optimize against.

6:54:00Obviously, filtration, we talked about it.

6:54:04There are probably Korean NBA fans, right?

6:54:06There is probably a bunch of stuff that is not necessarily material to the names and

6:54:14themes and stocks in our portfolio that really, really matter.

6:54:16So I want to make sure that I filter those out.

6:54:22There is this translate slash extract slash should I summarize, should I extract this

6:54:27into some sort of structured form.

6:54:29Again, so, so many ways to do this, so many ways to experiment, how to expose information

6:54:34to the model, and one of the reasons this is hard is it keeps changing.

6:54:39And obviously checking.

6:54:40Checking our own internal notes, our own internal views, potential conversations we have had,

6:54:46meeting recordings against these things.

6:54:48We actually need to cross-reference those things.

6:54:51Actually the idea of pulling information from disparate sources and cross-referencing them,

6:54:56that's super powerful.

6:54:58So you will see on the right here I have code, LLM, LLM, code, person.

6:55:03There's many, many ways to run these functions.

6:55:06I think about, oh, yeah, and finally, update.

6:55:10We update our views.

6:55:13There are many ways to run these functions.

6:55:15I think of each line as having a runner, and the most obvious one is code.

6:55:22Code is very good.

6:55:23It is fast, it is cheap, it is reliable, so for something like if the prices to earnings

6:55:30ratio is less than 15, I should just use deterministic code for that.

6:55:35Runner number two is statistics, classical machine learning, and you can imagine fitting

6:55:42the line to a regression for a specific pattern, this is very powerful because you can model

6:55:47much more complex relationships than just pure deterministic code.

6:55:52And for even more complex relationships, the reason we are all here, LLMs, AI agents, that's

6:55:58another type of runner.

6:55:59So for something like summarization, that's the state of the art.

6:56:04It's probably totally impossible to build a bunch of if statements that can summarize

6:56:10better than a modern LLM.

6:56:12Of course, people.

6:56:15People are important runners in the system.

6:56:18Imagine a function meeting the management team of a company.

6:56:22I probably don't want to send an LLM or an AI agent in to do that.

6:56:28I probably don't want to send an if statement into that meeting.

6:56:31I think there are many cases where because of judgment and the ability to navigate the

6:56:35real world and all of these things, a person is the best runner for a given piece of the

6:56:40function.

6:56:42I think this is a super, super important point.

6:56:45There is no glory in automating things for the sake of automating things.

6:56:49The goal is not to take as many things and make them LLM as possible for us.

6:56:54The goal is for any given piece of this function, what can I do to maximize absolute quality?

6:57:03And if you actually think about the function, it probably looks something like this.

6:57:07It's probably not just a linear statement of a bunch of different things.

6:57:11There's probably all kinds of branching logic and all kinds of ways to actually fork this.

6:57:16So maybe I want to collect the information and then translate it, and my main goal is

6:57:20to extract quotes and check those against sources to make sure that these are actually

6:57:24the things that people said, and that's my approach.

6:57:27But that might be totally wrong.

6:57:28Maybe what I want to do is I want to de-dupe and then I want to filter and then I want

6:57:33to pull external figures or maybe I want to do something totally different.

6:57:36I actually want to, I'm passing in a note first and I want to find other confirmatory

6:57:41data points or maybe I'm trying to red team.

6:57:43There's a million different ways to configure this.

6:57:46So yet again, more hyperparameters within the control flow, right?

6:57:52So many ways to think about just this very simple problem of pulling, filtering, summarizing

6:57:58aggregating the news for LLMs.

6:58:02And each of these boxes probably has an optimal runner, right?

6:58:09So the optimal runner might be deterministic code for collection, right?

6:58:15I'm pulling last 24 hours for a given source.

6:58:19That's deterministic code.

6:58:21Filtration?

6:58:23models maybe.

6:58:25LLMs?

6:58:25statistical methods, a combination, right?

6:58:29So this probably understates the complexity.

6:58:32The reality is most things are multi-runner.

6:58:34Most things have deterministic code plus LLM plus statistical method or human with LLM

6:58:39in conjunction.

6:58:41reality is it's probably combinatorics between my four buckets and there's even more

6:58:46buckets than that.

6:58:48Because within the LLM category I can tune the model.

6:58:52I can choose big model, small model, medium model.

6:58:55I can tune thinking effort. X high, high, medium, I can tune harness. I can choose the harness. I can

6:59:02choose which skills load with the harness. I can choose which hooks load with the skills.

6:59:05So yet again, more hyperparameters within my search space. I have an absolutely enormous

6:59:10amount of hyperparameters within my search space. And this is just for this one tiny problem, right,

6:59:15of just filtering the news. So the way to think about breaking down these problems is what can I

6:59:22actually compartmentalize in a way that we can understand and evaluate.

6:59:26That's what I'm hill climbing against.

6:59:28Otherwise I'm just tuning these things.

6:59:30I'm okay, that should actually be a machine learning system instead of an LLM.

6:59:34That should be a little model that we train.

6:59:36Oh, no, that shouldn't be a model at all.

6:59:38That should be an if statement.

6:59:39Or, oh, man, LLMs are really, really bad at translating that to portfolio impact.

6:59:44It should really be a human on that step, but they're using a deterministic system to

6:59:48help them search and pull the information.

6:59:51It could be all different things.

6:59:52And if you don't have a north star to hill climb against, you're just kind of, you're

6:59:57just fidgeting around.

6:59:59And I think I cannot convey enough that this is just one tiny thing we do.

7:00:04Imagine every single data source that we pull in, there's probably more than just three

7:00:09transformations to get them to the intermediate output.

7:00:11So the actual graph of Coatue and funds like Coatue, it actually probably looks, oh, not

7:00:18like this.

7:00:20is my screen saver.

7:00:22The actual graph probably looks something like this.

7:00:25It is probably massively complex.

7:00:28In each of those nodes, we just talked about at least ten hyperparameters with at least

7:00:3420 different values for them.

7:00:36So the search space is basically infinite.

7:00:39And figuring out how to actually lay this out in a way that you can comprehend both from

7:00:45technical perspective, but also absorb culturally, organizationally.

7:00:49That is the great challenge of applying AI in investing.

7:00:54And beyond investing, what we're really talking about is creating a state machine that can

7:01:00take information from the world and understand it well enough to make coherent decisions.

7:01:05There's use cases for this far and above, wider than just investment firms, in policy,

7:01:12in non-profits, in drug discovery, in corporate strategy.

7:01:16I think one of the most exciting things for me

7:01:19about being in forums like this

7:01:20is talking to other people in different spaces

7:01:23with different problems that kind of congeal

7:01:25on the same problem space.

7:01:27I'd love to keep talking about this.

7:01:29I'll hang out in the hallway afterwards.

7:01:30Here are my socials.

7:01:31And thank you, everyone, for your time.

7:01:34Thank you.