What it means
A business considers buying a smaller competitor, and the team prepares a memo explaining the price, expected benefits, integration costs and reasons the acquisition could disappoint. The investment committee can then compare the case with alternatives.
Start with the ask: the decision needed, the amount, timing and any conditions, so a reader does not have to infer the proposed commitment. Explain the thesis, meaning why this particular investment should create value and why now, and separate the central reason from supporting details.
Describe the asset or project, since a factory upgrade, fund stake and startup investment need different evidence even when each uses the memo format. Show the current facts with their sources, keeping historical performance and signed contracts distinct from forecasts and management claims.
Set a baseline of what happens if the organisation does not invest, assess market demand without assuming the entire market is available to one company, and present the full cost, including acquisition price or project capital, transaction expenses and follow-on funding. Map cash timing, because when money leaves and potential returns arrive matters, especially when liquidity is limited.
Show assumptions such as growth, margin, exit value and discount rate, which can drive a model more than the initial price, and make them easy to challenge. Test a base case and a plausible downside so decision-makers can see how sensitive the outcome is.
Net present value, internal rate of return or payback can inform a decision, but each has limits and none is a guarantee. Identify risks such as execution, financing, customer concentration, technology, compliance and integration, and explain mitigations, because a named owner, diligence step or contract condition is more useful than simply labelling a risk 'manageable'.
List open questions, since a memo can recommend further investigation instead of pretending uncertain facts are settled. Describe alternatives such as a smaller investment, partnership, delay or no action, and check strategic fit, because a profitable-looking project can still consume capacity needed for more important work.
Clarify governance by naming who prepared the memo, who reviewed it and who has authority to approve, and have any sponsor who stands to benefit disclose the interest under applicable policy. For an owner, the memo earns its space by making both the case and its weak points clear before money is committed, so avoid sales language and keep the core readable, with supporting exhibits.
If price or assumptions change before the vote, update the model and mark the new case; after approval, record the decision, conditions and rationale, and compare actual results with expectations. Carta describes startup investment memos covering business, finances, valuation, risks and terms, and a Stanford-hosted research brief examines memos as a tool for investment decisions and later review, though neither prescribes one universal format.
In practice
Real-world examples.
Example
A manufacturer's capex memo compares the output from a new production line with repair and outsourcing alternatives. It shows payback, net present value and the cash needed in each year. The committee can see that repairing the old line is cheaper now but costs more over five years.
Example
A venture investor documents valuation, market evidence, rights and downside risks before a vote. The memo separates signed customer contracts from management's pipeline claims. Partners can then challenge the weakest assumptions before any money moves.
Example
An acquisition memo updates its model after diligence reveals a customer concentration risk. The revised case lowers the price offered and adds a condition tied to retaining the largest customer. The earlier version is archived so the committee can see how the thinking changed.
Formula
Calculation
Illustrative hurdle check: projected IRR minus required hurdle rate = percentage-point gap. If a modelled IRR is 18% and the hurdle is 12%, the gap is 6 points. Clearing a hurdle is not approval or a guarantee; verify cash-flow assumptions and risk.
Worked example (fictional figures). A company considers spending $500,000 on a new production line expected to add $150,000 of net cash flow a year for 5 years, discounted at 10%. The present value of those inflows is $150,000 x 3.7908 = $568,620 (using the standard 10%, 5-year annuity factor), so net present value = $568,620 - $500,000 = $68,620. Simple payback = $500,000 / $150,000 = 3.3 years.
The positive net present value supports the case, but only if the $150,000 a year holds. If real cash flow is $120,000, the present value falls to $120,000 x 3.7908 = $454,896, and net present value becomes -$45,104, which is why the memo should show a downside case.Case study
Seen in the real world.
Fictional case: Northline Foods proposed a new warehouse in an investment memo. Its first model assumed immediate full occupancy. Reviewers asked for a slower ramp case, which lowered the projected return and led the company to stage the project instead of approving the entire build. The memo also listed the alternative of leasing third-party space for two years, which showed the board a cheaper route if demand disappointed.
The finance lead recorded the approval conditions in the minutes. Twelve months later the team compared actual occupancy with the memo's base and ramp cases and found it sat between them. This fictional case illustrates how a memo can improve a decision without dictating yes or no.
Watch out
Common mistakes.
- Presenting optimistic projections as established facts.
- Leaving out the no-investment alternative and the main downside case.
- Treating circulation of a memo as authority to commit funds.
Questions
People also ask.
Who writes an investment memo?
Usually the proposing or diligence team, with review from relevant financial and operational specialists.
Does a positive modelled return settle the decision?
No. Assumptions, risks, alternatives and formal authority still matter.
Should the memo be revisited later?
Yes. Compare actual outcomes with the original thesis and assumptions.
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