The Brittle Assumption: A Practitioner's Framework
Moving beyond risk identification to a systematic interrogation of the single point of failure in any investment thesis.
The Definition: The Sinkhole, Not the Storm
A Risk is a predictable storm on the horizon. You can see it coming, and you can build defenses—it is a known, potential headwind that might reduce returns.
A Brittle Assumption is the invisible sinkhole directly beneath your foundation. It is a foundational, often unstated belief whose failure causes the entire investment thesis to collapse. By the time you realize it’s there, the structure is already compromised. It is a catastrophic, not an incremental, threat.
Identifying these assumptions is the first step toward a more rigorous, defensible standard of judgment.
The Hunting Ground: A Framework for Identification
Brittle assumptions are not random; they typically fall into one of four key domains. This framework provides a systematic map for hunting them in the wild.
1. Market Assumptions (The “Pull”)
These are foundational beliefs about the external world: that a specific market need is urgent, that customer adoption will follow a predicted curve, or that a TAM is large enough to support a venture-scale outcome.
Example: The rapid-delivery startup bubble was built on the brittle market assumption that pandemic-level demand was a permanent behavioral shift.
2. Model Assumptions (The “Path”)
These are beliefs about the company’s internal machinery: that its proposed business model—its sales cycle, unit economics (LTV/CAC), and margin structure—is viable and will scale predictably.
Example: Believing a complex, high-ACV enterprise product can be sold effectively with a short, product-led sales motion.
3. Moat Assumptions (The “Pushback”)
These are beliefs about a company’s competitive advantage and the inaction of rivals. They assume that a moat (e.g., network effects, IP, brand) is defensible and that incumbents or new entrants will be slow to react.
Example: Assuming a well-funded, dominant incumbent will not allocate resources to launch a competing feature against a new entrant.
4. Management Assumptions (The “People”)
These are beliefs that the founding team possesses the unique, non-obvious skills and experience required to navigate the specific challenges of the market, the model, and the moat.
Example: Assuming a brilliant technical founding team has the requisite experience to navigate a complex, multi-year regulatory approval process.
The Arsenal: From Identification to Interrogation
Knowing where to hunt is only the first step. A true practitioner requires a protocol and the right tools.
Step 1: Acknowledge the Blind Spot
These four domains are precisely where human cognitive biases—confirmation bias, narrative fallacy, the planning fallacy—are most powerful. This is why even the most experienced investors miss them. Acknowledging that relying on intuition alone to hunt in these domains is a losing strategy is the first step toward rigor.
Step 2: Adopt a Protocol
The only effective defense against cognitive bias is a rigorous, formal protocol. The Clarity Framework™ is a purpose-built “interrogation protocol” designed to systematically hunt for brittle assumptions across all four of these domains, forcing a level of scrutiny that intuition alone cannot provide.
Step 3: Deploy the Engine
This protocol requires systematic, multi-dimensional stress-testing across hundreds of data points, comparing a thesis against historical failure patterns and internal data inconsistencies.
The question for any modern investment firm is not whether you need this level of rigor—it’s whether you can execute it at the speed and scale that today’s deal flow demands.
This is the design challenge that led us to build askOdin’s AI Judgment Infrastructure™. It is an engine built for one purpose: to power this protocol, turning a manual, intuitive art into a systematic, defensible science.
A Dialogue on Institutional Judgment
The Judgment Gap is an existential threat to funds facing the mathematical crisis of scaling capital and deal flow. In the AI era, running on artisanal, unscalable judgment processes is no longer a viable strategy. We are building the infrastructure to solve this.
If you are a partner or principal at a growing venture capital fund and are committed to building a more scalable, defensible, and rigorous investment process, we invite you to a confidential discussion.
Frequently Asked Questions
How is a brittle assumption different from a key risk?
A key risk is a known potential problem that might reduce returns. A brittle assumption is a foundational belief, often unstated, whose failure causes the entire investment thesis to collapse. It is the difference between a headwind and a catastrophic structural failure.
Can you give an example of a famous startup failure caused by a brittle assumption?
Many rapid-delivery startups in the early 2020s were built on the brittle market assumption that consumer demand would remain at pandemic-level highs and that their unit economic models would scale positively. When both assumptions proved false, their businesses collapsed.
How does askOdin’s AI find brittle assumptions that humans miss?
askOdin’s AI Judgment Infrastructure™ uses a proprietary process called The Clarity Framework™. It systematically interrogates an investment thesis across four key domains—Market, Model, Moat, and Management—to identify the single variable with the highest leverage and the lowest degree of proof. It turns an intuitive art into a systematic science.