Where Do You End and the Market Begin?
“The skin is the oldest and the most sensitive of our organs, our first medium of communication, and our most efficient of protectors.” - Ashley Montagu
You are here. The market is there. You make decisions. The market responds. You are the subject; the market is the object. You act upon it. You manage your risk within it. You navigate through it. The boundary between you and the market is as obvious as the boundary between your hand and the keyboard you are typing on.
Except it is not. That boundary, so intuitive, so deeply embedded in the language we use and the way we think, is a fiction. A useful fiction, granted. A fiction that makes decision-making tractable and risk management conceivable. But a fiction nonetheless, and one whose quiet unravelling changes everything about how you should think about your role in the system you are trading.
Because you do not act upon the market. You act within it. Your stop loss is not a private decision; it is a market order that, when triggered, contributes to the move that triggered it. Sizing that you think of as a personal risk preference is really a liquidity event, one that shapes the market’s microstructure at the exact moments your strategy is most engaged. And your inaction during a drawdown is not neutral either. It withholds capital that would otherwise be in play, feeding the very regime you are waiting to pass.
There is no outside. There is only inside, with varying degrees of awareness about the fact.
The Cell Wall
Biology offers a more honest model than finance for thinking about boundaries.
A cell wall is not a barrier. It is a membrane. It is selectively permeable, allowing certain molecules to pass while blocking others. It is not a wall between inside and outside but a dynamic interface that regulates the relationship between the cell and its environment. The cell is defined by this interface, not separated by it.
And the membrane itself is alive. It responds to conditions, adjusting its permeability, changing what it admits and what it expels according to the environment’s chemistry and the cell’s needs. The boundary between the cell and its environment is not fixed. It is negotiated, continuously, in real time.
More than this, the cell depends on its environment for survival, and the environment is partly composed of the outputs of cells. The oxygen one cell exhales, another cell breathes. The nutrients one organism releases, another organism absorbs. The boundary between organism and environment is functionally porous: what is inside at one moment becomes outside at the next, and vice versa.
Your relationship with the market has exactly this quality. You take in information (prices, news, data) and you emit actions (orders and cancellations). Your actions become part of the environment that other participants take in. Their responses become the information you absorb. There is a continuous flow of material across the boundary, and the boundary itself is not a wall but a membrane, permeable, dynamic, and fundamentally unable to separate you from the system you inhabit.
Your Stop Loss Is a Market Force
Consider the most basic risk management tool: the stop loss. In the standard framing, a stop loss is a private decision. You decide the price at which you will exit a losing position. The stop protects you. It limits your downside. It is a tool you use upon the market, from outside, to manage your exposure.
Now consider what actually happens when a stop loss triggers. Your sell order enters the market. If you are trading a liquid instrument, the impact may be negligible. But you are not alone. Thousands of other participants have set stop losses at similar levels, because the same technical analysis, the same risk management principles, and the same volatility calculations all point to similar prices. When the market reaches that zone, the stops trigger collectively. A wave of selling hits the order book at precisely the same moment.
This collective selling drives the price lower. The lower price triggers more stops, set at slightly more distant levels by slightly more conservative participants. More selling. More downward pressure. The cascade feeds itself, and the move that triggered the original stops is amplified by the stops themselves.
Your stop loss did not protect you from the market. Your stop loss, along with everyone else’s stop losses, became the market. What started as a private decision turned into a collective force, and the tool built to manage risk had quietly become a mechanism for generating it. The line between “your risk management” and “the market’s dynamics” dissolved the moment the order was placed.
This is not an edge case. It is how modern markets normally operate. Every stop loss is at once a risk management decision and a contingent market order, just as every position is both a private holding and a component of aggregate positioning. And a rebalancing schedule, however routine, is also a contribution to systematic capital flows that shape the very instruments being rebalanced.
There is no version of participation that is purely private. Every act within the market is also an act upon the market. The distinction between managing your risk and creating systemic risk is not a bright line. It is a gradient, and you are always somewhere on it.
The River and the Bank
A river shapes its banks. This is obvious: the water erodes, deposits, carves, and moulds the land through which it flows. But the banks also shape the river. The contours of the land determine the river’s path, its speed, its depth, the patterns of its eddies and currents. Change the bank and you change the river. Change the river and you change the bank.
Which came first? The question is meaningless. The river and the bank co-evolved. Neither existed independently and then influenced the other. They emerged together, in a continuous process of mutual shaping that has no beginning and no end. The boundary between river and bank is visible to the eye, but functionally, they are a single system. You cannot understand the river without understanding the bank, and you cannot understand the bank without understanding the river.
The embedded agent is both river and bank. Your strategy is a flow of capital through the market’s structure. The market’s structure channels your capital, directs it, constrains it, and absorbs its impact. But your capital also shapes the structure. Your orders carve channels. Your exits create eddies. Your persistence over time erodes some features and builds up others.
You are not navigating a fixed landscape. You are flowing through a landscape that your flow is reshaping, and the reshaped landscape is redirecting your flow. That separation between navigator and terrain is a conceptual convenience that bears no relationship to the structural reality.
Structural Coupling
The biologist Humberto Maturana introduced the concept of structural coupling to describe the relationship between an organism and its environment. Two systems are structurally coupled when the structure of each is shaped by its ongoing interaction with the other. Neither system determines the other, but each constrains and triggers changes in the other through their mutual engagement.
A classic example: a tree and the soil it grows in. The tree’s roots stabilise the soil. The soil’s composition determines what the tree can absorb. The tree’s fallen leaves enrich the soil. The enriched soil supports more growth. Remove the tree and the soil changes. Change the soil and the tree changes. They are structurally coupled: distinct in form but inseparable in function.
Markets and their participants are structurally coupled in the same way. The market’s structure (its liquidity, its volatility, its regime dynamics) constrains and shapes the strategies that operate within it. Those strategies, in turn, reshape the market’s structure through their collective actions. Neither is prior to the other. Neither can be understood in isolation. They co-specify each other in an ongoing process that has no pause button and no external reference point.
This has a disorienting implication for how we think about risk. In the standard framework, risk is something external. The market presents risks. You assess them. You manage them. Risk exists out there, and your job is to protect yourself from it, from in here.
In a structurally coupled system, this separation collapses. Risk is not something the market presents to you. Risk is something you co-create with every other participant. Your positioning contributes to the aggregate risk structure. Your hedges create the very correlations they are designed to protect against, when enough participants hedge the same way. Your inactivity during a crisis deepens the liquidity vacuum that defines it.
You do not manage risk from outside the system. You co-produce risk from inside it. And the risk you co-produce feeds back into the conditions you experience.
Inaction Is Action
Perhaps the most subtle consequence of the dissolved boundary is this: in a complex adaptive system, doing nothing is doing something.
When a market crashes and you choose not to sell, that choice is an action. It withholds selling pressure that would otherwise become part of the market’s search for a clearing price. It maintains a position that contributes to aggregate exposure. It alters the balance of order flow, even though nothing has been submitted. Your inaction shapes the system as surely as your action would, just differently.
When you choose to stay in cash during a rally, that cash is capital withheld from the market. It is liquidity that is not providing support, buying power that is not contributing to momentum, a position that shapes the market’s structure through its absence. The market with you fully invested is a different market from the market with you in cash, even if you have not placed a single order.
This is what it means to be inside a system with no outside. Every state you occupy is a state within the system. Invested, flat, hedged, leveraged, inactive: each is a configuration of your presence within the market, and each configuration has consequences for the system’s dynamics. There is no neutral position. There is no way to step out of the frame.
The embedded agent who understands this recognises that risk management is not about controlling your exposure to the market. It is about understanding that your exposure is the market, at least a piece of it. Your decisions, including your decision not to decide, are structural contributions to the system you are trying to navigate.
The Immune System Metaphor
The immune system defines “self” by engaging with “non-self.” Without pathogens, without foreign bodies, without external challenge, the immune system cannot establish the boundary between the organism and its environment. The self is not pre-given. It is constructed through interaction. Remove the interaction and the boundary dissolves.
This is precisely the situation of the embedded agent. Your identity as a trader, as a strategy, as a risk-taking entity, is not pre-given. It is constructed through your interaction with the market. Your strategy is defined by the patterns it responds to. Your risk profile takes its shape from the conditions it encounters. Your edge exists only in the ecology it operates within. Remove the market, and the strategy is meaningless code. Remove the strategy from the market, and the market loses one of its constitutive agents.
You are not a thing that trades the market. You are a process that is partly constituted by the market and that partly constitutes the market. The boundary between self and environment, between agent and system, is not a wall you stand behind. It is a dynamic interface you continuously negotiate, and the negotiation is the trading.
Building for a World That Includes You
If the boundary between you and the market is a useful fiction, then what changes in practice?
Everything about how you think about risk, for a start. If risk is co-created, then your risk management must account for your own contribution to the risk landscape. This means sizing not just for the historical distribution of returns, but for the distribution that includes your participation and the participation of everyone who trades like you. It means recognising that your stops, when they cluster with others, are not just protection: they are vulnerability. It means understanding that your portfolio, viewed in isolation, tells you something useful, but viewed as part of the aggregate, tells you something different and often more important.
It changes how you think about edges. If your edge exists only in relationship to the ecology, then the edge is not something you possess. It is something you maintain through the quality of your participation. The moment you stop monitoring the ecology, stop adjusting to its shifts, stop respecting the feedback between your actions and their consequences, the edge dissolves. Not because it was taken from you, but because the relationship that constituted it has changed.
And it changes how you think about yourself as a participant. You are not an observer who happens to trade. You are a structural element of the system. Your presence matters. Your absence would matter. Your decisions ripple outward in ways you cannot trace and influence dynamics you cannot observe. This is not grandiosity. It is the simple consequence of being coupled to a system in which every component is coupled to every other.
The embedded agent who accepts the dissolved boundary does not grieve the loss of the outside view. The outside view was never available. What the agent gains instead is a more accurate understanding of their actual position: not a scientist studying a specimen, but a cell within an organism, defined by its relationships, sustained by its exchanges, and inseparable from the system it helps to constitute.
There is no outside. There never was. The boundary between you and the market is a story you tell yourself so that the complexity becomes manageable. It is a good story. A necessary one. But still a false one. The embedded agent lives in the truth that the story obscures: you are not separate from the market. You are the market, in part, and the market is you, in part, and the boundary between those parts is drawn in pencil on water.
Richard Brennan writes on systematic trading, complex adaptive markets, and the philosophical foundations of trend following at atstradingsolutions.com. His books include The Fractals of Finance and Complex Adaptive Markets. The forthcoming Carved by Impossibility completes the trilogy.
Want the theoretical foundation for why trend following works?
The Fractals of Finance: Determinism, Adaptation and the Geometry of Markets
The book explores the full architecture of feedback, fat tails, and fractal structure in financial markets, and what it means for how we trade, invest, and understand risk.
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