The Unbuy Decision
Sell by retesting the thesis and opportunity cost, not reacting to price.
- Difficulty
- Advanced
- Time to result
- ~ongoing to results
- Steps
- 6
- Confidence
- 98%
The Unbuy Decision reframes selling as the inverse of buying. Instead of reacting because a position rose, fell, doubled, or appears embarrassing, the investor revisits the original thesis and values the asset from the present forward. The analysis asks what is owned, why it was purchased, how the fundamentals and competitive position have evolved, what return continued ownership may produce, and where the capital could earn more. A static bargain bought for fifty cents may logically be sold near one dollar because its discount has closed. A rare business capable of compounding intrinsic value for decades may remain attractive even after a large gain or temporary overvaluation. The framework therefore combines thesis discipline, forward-looking valuation, and opportunity cost while excluding regret avoidance and price action as standalone reasons.
Origin
Howard and Andrew Marks developed the idea during their most animated exchange for the Something of Value memo and later revisited it in Howard's Selling Out memo.
Core principles
- 01Selling should reverse the original buying analysis.
- 02Price movement alone is not a fundamental reason to sell.
- 03Reassess what you own, why you own it, and what has changed.
- 04Compare continued ownership with the best available alternative.
- 05Exceptional compounders deserve patience but require exceptional evidence.
How to run it
- 1
Reconstruct the Buy Case
Write down why the investment was originally attractive and what outcome you expected.
Pro tip Separate the business thesis from the entry price.
Watch out Do not rewrite the original thesis to match subsequent events.
- 2
Update the Fundamentals
Assess changes in competitive advantage, management, cash-flow potential, risks, and the probability of the expected outcome.
Pro tip Focus on evidence that changes intrinsic value, not merely sentiment.
Watch out A rising price does not prove that fundamentals improved.
- 3
Value From Today
Estimate the return a new buyer could reasonably expect at the current price.
Pro tip Ignore your cost basis; it does not determine future cash flows.
Watch out Past gains can make an unattractive current return feel safer than it is.
- 4
Calculate Opportunity Cost
Compare continued ownership with cash and the best realistic alternative investment.
Pro tip Include differences in risk, tax, liquidity, and confidence.
Watch out Do not evaluate a sale in a vacuum when the proceeds must go somewhere.
- 5
Classify the Asset
Decide whether the holding is a finite discount-closing opportunity or a rare long-duration compounder.
Pro tip Demand strong evidence before granting a company compounder status.
Watch out Most businesses cannot compound intrinsic value at high rates for decades.
- 6
Unbuy Deliberately
Sell when the thesis has failed, expected return is inadequate, or a materially better opportunity exists.
Pro tip Record the reason so the decision can be reviewed independently of later price moves.
Watch out Do not sell merely to avoid feeling foolish if the price falls.
In the wild
An investor buys a security worth roughly one dollar for fifty cents. The asset has no meaningful mechanism for increasing intrinsic value, and the price subsequently reaches one dollar. Reapplying the buying analysis shows that the original discount has disappeared.
→ The investor sells and searches for another opportunity with a better prospective return.
An investor owns a company capable of compounding intrinsic value near 20 percent for a long period. Although the market price has doubled and temporarily exceeds a simple point estimate, the company's forward compounding and scarcity remain more attractive than available alternatives. The investor continues holding while monitoring whether the compounding thesis remains valid.
→ The investor avoids sacrificing decades of potential value creation merely to lock in an early gain.
Common mistakes
Selling Because It Is Up
A gain says nothing by itself about whether future intrinsic value remains attractive relative to price.
Selling Because It Is Down
A decline is not a reason to exit unless it reflects a broken thesis, excessive risk, or better opportunity cost.
Calling Every Winner a Compounder
Price appreciation can be confused with intrinsic compounding. Verify the underlying economics and durability.
Is it for you?
Best for
It is best for long-term investors deciding whether to hold, trim, or exit an existing position.
Not ideal for
It is not ideal for rules-based trading strategies with deliberately predefined price exits.
From the transcript
“you should make your selling decision based on why you made the investment and how things have evolved”
“most people make selling decisions based on price action if it's up or if it's down or whatever”
“maybe we can think better about the selling decision if we rebrand it and we call it the decision to unbuy”
From the episode
Howard Marks & Andrew Marks: Something of Value
Howard Marks