Fast Intuition, Slow Checks
Harness investment intuition while using deliberate review to control bias
- Difficulty
- Advanced
- Time to result
- ~ongoing to results
- Steps
- 6
- Confidence
- 94%
Fast Intuition, Slow Checks combines rapid expert judgment with deliberate analytical control. Experienced investors often recognize patterns before they can fully explain them, making intuition a valuable source of ideas. The same fast thinking, however, is vulnerable to overconfidence, confirmation bias, anchoring, and inconsistent temperament across a team. The framework therefore preserves the initial signal but requires a slower phase: articulate the thesis, identify likely biases, examine contrary arguments, test what is already priced in, and define invalidation evidence. The review does not end when a position is opened. Managers repeatedly check the thesis as new information arrives, creating consistency without forcing every person to share the same temperament.
Origin
Extracted from Masters in Business, where Matt Egan applied the fast-and-slow thinking model to a growing team of portfolio managers.
Core principles
- 01Preserve expert intuition because it can identify opportunities quickly
- 02Assume intuitive judgments can contain behavioral biases
- 03Slow down before committing capital
- 04Keep testing a thesis after the initial decision
- 05Teach team members to recognize their own temperaments
How to run it
- 1
Capture the fast judgment
Record the intuitive opportunity or concern before extended analysis alters the initial perception.
Pro tip State what pattern triggered the judgment and why it may matter.
Watch out Do not mistake speed or conviction for accuracy.
- 2
Name the likely biases
Identify which behavioral tendencies could be shaping the judgment, such as anchoring, loss aversion, or confirmation bias.
Pro tip Tailor the bias list to the decision maker's known temperament.
Watch out A generic bias checklist is less useful than honest self-assessment.
- 3
Write the thesis
Specify the expected mechanism, current price assumptions, time horizon, and evidence that would invalidate the idea.
Pro tip Separate the fundamental thesis from the expected market catalyst.
Watch out A thesis that cannot be disproved is not a useful decision tool.
- 4
Run the slow checks
Examine fundamentals, valuation, market technicals, positioning, and the strongest opposing argument.
Pro tip Assign someone to argue the other side when decisions involve a team.
Watch out Do not use analysis merely to justify an action already chosen.
- 5
Decide and size
Proceed only when the slow analysis supports the intuition, sizing the position according to evidence and downside risk.
Pro tip Reduce size when the opportunity is attractive but uncertainty remains high.
Watch out Binary buy-or-reject thinking can conceal useful sizing choices.
- 6
Recheck after action
Review the thesis at predefined intervals and when material evidence changes.
Pro tip Compare new facts with the original written thesis rather than with the current profit or loss.
Watch out Price appreciation does not prove the thesis was correct.
In the wild
A manager senses that panic selling has made a corporate bond unusually cheap. Before buying, the team writes the recovery thesis, checks liquidity and refinancing risks, identifies its tendency toward contrarian overconfidence, and assigns another analyst to present the bearish case.
→ The position is taken only after intuition survives a structured challenge, and its size reflects unresolved risks.
A growing portfolio team asks each manager to document personal biases and use the same slow-review questions for major positions. Managers retain distinct styles, but their theses and invalidation conditions become comparable.
→ The organization improves decision consistency without eliminating individual judgment.
Common mistakes
Suppressing intuition entirely
Removing fast judgment can discard expertise accumulated through repeated market observation.
Using checks as confirmation theater
A review has no value if it only collects arguments supporting the initial decision.
Ignoring individual temperament
Different managers have different biases, so one undifferentiated control process may miss their most likely errors.
Is it for you?
Best for
It is best for portfolio managers and investment teams whose decisions combine judgment, research, and incomplete information.
Not ideal for
It is not ideal for purely mechanical strategies whose rules already determine every decision.
From the transcript
“I want people to really understand what their bias is.”
“the fast part reminds me is that that's the intuitive side of investing right”
“the slow part, which is more difficult to slow down and really think about. That's sort of the checks.”
From the episode
Fixed Income Credit Analyst to Bond Manager With Loomis Sayles