This is for DIY investors who are about to make a portfolio change large enough to second-guess later: trimming a concentrated winner, raising cash, replacing a fund, or rebalancing across taxable and retirement accounts. The job is simple: write the decision note before the trade ticket is entered, while the reason, risks, and review rule are still separate from the next market move.
As of 2026-04-23, tax rules, broker reporting requirements, and fund details cited below are summarized from IRS publications, FINRA investor education, index methodology pages, and issuer fund pages. Verify the source pages before acting. This article is educational, not tax, investment, or legal advice. Consult a qualified professional for your situation.
A major portfolio change is not a universal number. Your written policy might define it as a trade that changes a holding by 5 percentage points or more, moves cash outside a target range, alters income you rely on, or swaps one index exposure for another. Open Deep Digital Ventures Portfolio Tracker while you write the note so the position size, account mix, and planned after-trade allocation are visible before you place the order.
The Quick Note
Before the trade, write the before state, the after state, and the rule that will decide whether the trade worked. Do not write “rebalance” or “raise cash” by itself. A useful note says, “This moves cash from 3% to 8%,” or “This trims one holding from 18% to 12%,” or “This replaces broad U.S. market exposure with large-cap U.S. exposure.” Those numbers make the decision reviewable.
- Decision: the trade you are considering, the account involved, and the target weight after the trade.
- Reason: the one main reason, such as concentration control, withdrawal funding, index cleanup, income risk, or tax-lot management.
- Source checked: the issuer page, index methodology, broker screen, earnings release, or written allocation rule you used.
- Base case: what you expect to happen if the trade does its job.
- Downside case: what gets worse if you are early or wrong.
- Execution: whether you will use a market order, limit order, staged orders, or no trade if the spread is wider than your rule.
- Income or tax note: only include this if the trade changes expected distributions, creates a taxable sale, or depends on specific lots.
- Review rule: the date or event that will trigger review, such as the next quarterly allocation check, fund distribution, earnings report, withdrawal cycle, or year-end tax document review.
Scenario Note Template
- Portfolio change:
- Account affected:
- Position or fund:
- Before weight:
- Target after weight:
- Main reason:
- Source checked:
- Base case:
- Upside case:
- Downside case:
- Risk reduced:
- Risk added:
- Income or tax impact:
- Order type:
- Review date or event:
- Action rule:
- What would make this wrong:
Keep the template short enough to use. If a note cannot fit on one screen, the trade may need a separate investment memo. For most allocation changes, 12 to 16 lines are enough if the weights, source, downside case, and action rules are specific.
Why Scenario Notes Help
Scenario notes turn a portfolio change into a testable decision. If the idea came from a broker, adviser, newsletter, earnings call, ETF issuer page, or your own allocation rule, write that source down. The note still needs to say why the change fits your household portfolio, not only why it sounded reasonable when recommended.
The note should separate four things: what you expect, what would go better, what would go worse, and what you will do if each path starts to show up. That makes the later review about process quality, not hindsight.
| Scenario | What to write before the trade |
|---|---|
| Base case | The most likely reason for the change, stated with current weight, target weight, account type, and review date. |
| Upside case | What improves if you are right, such as lower concentration, more cash for withdrawals, better index fit, or lower fund cost. |
| Downside case | What gets worse if you are early or wrong, such as cash drag, missed income, taxable gain, or replacement risk. |
| Action case | The exact trigger for adding, trimming, holding, or reversing the trade, plus the order type you plan to use. If execution price matters, check how the order type works before entering it.[1] |
What to Check Before the Change
Use sources only when they change what you write in the note. For an ETF swap, check the fund issuer page and the index methodology so the note says what exposure is being sold and what exposure is being bought. A fund name alone is not enough if the change narrows, broadens, or shifts the benchmark.[2][3][4]
- Index fit: whether the new exposure matches the intended benchmark, such as broad U.S., large-cap U.S., total international, or bond exposure.
- Fund cost: whether the expense ratio meaningfully changes the reason for the trade.
- Income timing: the next expected dividend or distribution month, especially if the portfolio funds withdrawals.
- Execution rule: whether quick execution matters more than price control, and whether the trade should be staged.
- Tax lots: whether the sale creates a gain or loss, which lots are selected, and whether replacement purchases could affect the loss.
For taxable accounts, add one tax note before selling. If the trade realizes a loss and you buy substantially identical stock or securities within 30 days before or after the sale, the wash-sale rule may affect how the loss is treated.[5][6] If older lots are involved, write whether the broker shows covered or noncovered basis and keep the broker lot report with the note.[7]
Dividend-income investors should also record the expected payer, account, and distribution timing before changing a position. The point is not to turn the note into a tax file. The point is to avoid discovering after the trade that the income schedule or account location mattered more than the price chart.
Example: Trimming a Winner
Here is a worked example using portfolio weights, not a recommendation. An investor has one appreciated holding at 18% of total household investments across a taxable brokerage account and an IRA. The written policy says no single holding should stay above 15% after a review unless the investor writes a fresh exception. The proposed trim takes the position to 12%, leaves room for normal price movement, and avoids turning a risk-control trim into a full exit.
| Line item | Write this before the trim | Review trigger |
|---|---|---|
| Position weight | Trim from 18% to 12%, not below the long-term target unless the downside case starts. | Review if the position moves back above 15%. |
| Reason | Concentration risk is now larger than the original thesis. | Review after the next earnings report or quarterly allocation check. |
| Upside case | The company or fund keeps compounding and the smaller position still contributes. | Do not rebuy only because the price rises. |
| Downside case | Expectations reset and the 18% weight would have been too large. | Do not add until the downside facts are reviewed. |
| Execution | Use a limit order or staged orders if the spread is wider than your rule. | Compare the fill with the planned price range. |
For index ETFs, name the source you checked once. If you are replacing a broad U.S. market ETF with an S&P 500 ETF, the note should say that the replacement is narrower. If you are replacing U.S. exposure with international exposure, the note should say which benchmark or fund page supports that shift. The useful fact is the exposure change, not a long list of ticker symbols.
If the trim is in a taxable account, write the selected lots, holding period category, and expected gain or loss. If the tax result is material, attach the broker lot screen and save the review for the year-end tax forms instead of guessing from memory.
Example: Raising Cash
Raising cash needs a redeployment rule. Without one, the note often becomes “I felt nervous,” and the review has no standard. A retiree might raise cash from 3% to 8% to fund planned withdrawals; a FIRE investor might raise cash because an employer stock sale or year-end tax payment is coming; a dividend investor might raise cash because one income holding has become too large.
- Purpose: write the use of cash, such as 6 months of withdrawals, a scheduled tax payment, or dry powder for a pre-written rebalance rule.
- Funding source: sell the assets most above target first, rather than selling the most emotionally frustrating holding of the week.
- Portfolio after trade: record the new stock, bond, cash, U.S., international, and income exposure.
- Redeployment trigger: define the rule before the sale, such as “deploy 2 percentage points if equities fall 5 percentage points below target” or “rebalance at the next quarterly review if no trigger occurs.”
- Expiration date: if the cash still has no use after the review date, decide whether it returns to the strategic allocation.
Execution belongs in the scenario note too. Market orders prioritize execution, while limit orders set a price boundary but may not fill.[1] For a large ETF trade, the note should say whether quick execution matters more than price control, and whether the trade will be placed during normal market hours or staged across more than one order.
Review the Note After the Outcome
Review the note after the next defined event, not after every noisy price move. Good review points include the next quarterly allocation check, next fund distribution, next earnings report, next withdrawal cycle, or the arrival of year-end broker forms.
- Did the base case happen, or did the upside or downside case appear first?
- Did the trade match the written before-and-after weights?
- Did the order type work the way the note expected?
- Was the source still the right source, such as the issuer page, index methodology, broker confirmation, or tax-lot report?
- If the action rule triggered, did you follow it?
Use the review to update your process. If the downside case happened and you froze, lower the maximum position size for that type of holding. If cash stayed unused past the expiration date, tighten the redeployment rule. If a fund swap changed exposure more than expected, require issuer-page and index-methodology checks in the next note.
FAQ
Do scenario notes need to be long?
No. A useful note can be 12 lines if it includes the trade, account, before weight, after weight, source checked, downside case, action rule, and review date.
Should every trade have scenarios?
No. Use a full note for trades that are large under your own policy, move cash outside your target range, create a new top holding, alter expected income, or affect a taxable sale.
What if the idea came from a broker or adviser?
Write that down. Record the recommendation source, the alternative you considered, the account affected, and the reason the change fits your own allocation policy. A recommendation is not a substitute for your own written decision record.
How should dividend investors use scenario notes?
Record the payer, account, expected distribution month, income concentration, and withdrawal relevance before the trade, especially if the holding helps fund spending.
Can the note be written after the market moves?
Write the decision note before the order. After the order, write a review note. Mixing the two makes it too easy to turn hindsight into a reason that did not exist when the trade was placed.
Sources
- FINRA investor education on stock order types: https://www.finra.org/investors/investing/investment-products/stocks/order-types
- Vanguard ETF profile pages for checking fund exposure and costs: https://investor.vanguard.com/investment-products/etfs
- S&P U.S. Indices Methodology for S&P 500 and related U.S. index exposure: https://www.spglobal.com/spdji/en/methodology/article/sp-us-indices-methodology/
- FTSE Global Equity Index Series Ground Rules for global equity index construction: https://www.lseg.com/content/dam/ftse-russell/en_us/documents/ground-rules/ftse-global-equity-index-series-ground-rules.pdf
- 26 CFR 1.1091-1 wash-sale regulation: https://www.ecfr.gov/current/title-26/section-1.1091-1
- IRS Publication 550 on investment income and expenses: https://www.irs.gov/publications/p550
- IRS Publication 551 on basis of assets: https://www.irs.gov/forms-pubs/about-publication-551