Start with what the money must buy.
This fictional household wants €100,000 in today’s purchasing power in 15 years. The long-term amount and date are flexible; essential spending and a nearby bill come first. Follow its decisions, compare a second complete case and try the independent tasks below. Nothing needs submitting; keep real working notes private, without account numbers or identifying details.
Assign the available money once.
- 1 · €10,000 · reserveAccessible bank cash
- 2 · €15,000 · nearby billSeparate bank cash; due in 24 months
- 3 · €35,000 · long-term portfolioBroker holdings; no investment borrowing
Monthly take-home income is €3,000; spending, including irregular bills, is €2,600. That leaves €400 to contribute now. Neither the €10,000 reserve nor the €15,000 bill cash belongs in the long-term allocation.
Check the boundary before applying percentages
€10,000 + €15,000 + €35,000 = €60,000. Any long-term weights apply to €35,000, not €60,000. A 60% share weight would mean €21,000; applied to all savings it would mean €36,000, claiming money already assigned to other jobs.
For a draft with several goals, show all assignments together. Restricted money stays labelled restricted. Excluding reserve from a target does not remove its role in wider finances.
Test the funding before choosing weights.
Here €400 keeps its purchasing power: nominal additions must rise with inflation. All bars show today's euros, on one €0–€140,000 scale. The vertical marker is the €100,000 goal.
-2% real each year€88,016 · €11,984 short
0% real each year€107,000 · €7,000 above the goal
+2% real each year€130,872 · €30,872 above the goal
Keep €400's purchasing power
0% real return → €107,000 in today's euros
Keep the transfer fixed at €400 nominal
0% real return, 2% annual inflation → €97,240 in today's euros
In the fixed-transfer case, the goal costs €134,587 in future nominal euros. Investment costs are included in the assumed rates; personal tax is omitted. Constant rates show sensitivity, not market paths or chances of success.
The −2% real case leaves about €11,984 missing. Reaching €100,000 under that same assumption would need about €478 each month in today’s purchasing power. The current €400 surplus cannot fund that change: compare affordable additions, a smaller goal or a recalculated later date.
Calculate dated additions and keep the price bases separate
For an annual effective rate r, the monthly rate is m = (1 + r)^(1/12) − 1. With 180 end-month additions, the ending balance is €35,000 × (1 + m)^180 + €400 × ((1 + m)^180 − 1) / m. At zero return it is simply €35,000 + 180 × €400 = €107,000. Future additions do not receive fifteen years of returns on day one.
The real-rate cases use a constant real addition: its nominal amount must rise with inflation. Today’s budget does not establish that future income can support this. At −2% real, the required monthly real addition is about €477.11, rounded up to €478; a different date or amount needs a new calculation.
The fixed nominal €400 case instead assumes 2% inflation and zero net real return, hence 2% nominal return. It ends at about €130,872 in future nominal euros. Divide by 1.02^15 to get €97,240 in today’s euros. The goal itself costs about €134,587 future nominal euros, leaving roughly €2,760 of today’s purchasing power unfunded. The identical-looking €130,872 in the +2% real case has a different price basis.
These rates are sensitivity assumptions, not returns assigned to a share/bond mix. Fluctuating returns, interruptions, taxes and changed spending can produce different results.
Record the trade-off behind the mix.
The household prefers more broad-share exposure for the flexible long-term goal, but rejects a mix losing more than €8,000 when shares fall 30% and bonds fall 5%. This is a stated willingness for one exercise, not a maximum loss guarantee or measured capacity.
All bars start at zero and use a €35,000 scale. Solid = shares; hatched = bonds. No flows, costs, taxes or currency changes.
A · 30% shares / 70% bonds
Shares €7,350 + bonds €23,275 = €30,625
Loss €4,375 · 12.5% of the portfolio
B · 60% shares / 40% bonds
Shares €14,700 + bonds €13,300 = €28,000
Loss €7,000 · 20% of the portfolio
C · 80% shares / 20% bonds
Shares €19,600 + bonds €6,650 = €26,250
Loss €8,750 · 25% of the portfolio
These events compare consequences. They have no assigned probabilities and are neither forecasts nor worst-case limits.
C fails that condition. A and B pass; the household carries B forward, accepting €2,625 more loss than A for greater share exposure. A remains reasonable if the smaller loss matters more. The full comparison also shows the opposite event. No single mix follows from the goal’s date or these shocks.
What if contributions stop when markets fall?
Shares −30%, bonds −5%; then prices stay unchanged in this scenario. Income falls to €1,800/month; spending stays €2,600. The bill rises to €20,000, due at the end of month 6. Pause contributions before the next transfer; €800 each month still needs funding. Bank cash is accessible.
If low income continues in month 7: another €800 spending gap − €200 reserve left = €600 still unfunded.
Pay the extra €5,000 from reserve
Reserve €5,200 → €200; portfolio B stays €28,000.
Or sell €5,000 of portfolio B
Portfolio €28,000 → €23,000; reserve stays €5,200.
The branches are alternatives. A sale cuts long-term funding and requires proceeds before the bill. Timely receipt is assumed for the arithmetic; the actual provider's withdrawal terms still need checking. Interest, inflation, costs, tax and currency changes are omitted here.
Follow the six monthly gaps and the other structures
Pausing the €400 addition stops an extra outflow; it leaves €2,600 − €1,800 = €800 to fund each month. Six months use €4,800 of reserve: €10,000 − €4,800 = €5,200. The six planned additions, €2,400, never became spare money.
The bill needs €20,000 − €15,000 = €5,000 more. Using reserve leaves €200. If the income gap continues, month 7 needs €800 − €200 = €600 elsewhere. The month-6 bill was paid; the new gap belongs to the next month's spending.
Alternatively, a €5,000 portfolio sale leaves A: €25,625; B: €23,000; C: €21,250. All three preserve the same €5,200 reserve in this branch. The sale reduces the long-term goal's capital; it does not establish which holdings to sell.
Before relying on either branch, establish how long the income gap might last, which spending or deadlines can change and when sale proceeds would arrive. A lower share weight alone cannot answer those questions. For ongoing withdrawals, the two return sequences show why timing matters too.
Keep the decision and the unfinished work together.
Keep the baseline plan below separate from the combined-stress example. Figures and rules belong to this fictional exercise.
- Goal and priority
- €100,000 in today's euros in about 15 years. Amount and date can change; the nearby bill and essential spending come first.
- Affordable additions
- €3,000 monthly take-home income less €2,600 spending, including irregular bills, leaves €400 to contribute. €400 is affordable now; a constant real addition requires later increases with inflation. Pause or reduce after a funding change.
- Funding basis
- €35,000 plus 180 end-month additions of €400 in today's purchasing power ends at about €88,016 / €107,000 / €130,872 under −2% / 0% / +2% constant real returns. The lower case needs a changed goal or funding; no rate is promised.
- Investment roles and choice
- €21,000 broad shares for growth; €14,000 bonds to moderate fluctuations. B meets the stated €8,000 loss criterion for the tested shock, with more shares and €2,625 more loss than A. A remains defensible. Both holdings can lose more in other events.
- Loss response
- Pause additions if the budget no longer funds them; identify remaining spending gaps and cash dates. Reserve use reduces protection; a sale reduces long-term capital. Recalculate the flexible goal after reassignment.
- Implementation record
- Investment types understood; products not selected. Keep identities, costs, country rules, provider checks and access terms in separate supporting records.
- Maintenance rule
- Check quarterly; accept shares at 55–65% of current portfolio value (±5 percentage points from 60%). Outside the band, first confirm suitability, then restore using available contributions and further adjustment after checking costs/taxes.
- Attention and revision
- Review the full plan annually and after material changes to goals, income, obligations, access or product terms. Handle genuine security problems promptly; record non-urgent ideas for review.
Illustrative review dates: allocation 22 January 2027; full plan 22 October 2027. The supporting records are placeholders to create privately, not evidence supplied by this exercise.
Try a household with different constraints.
An independent fictional household has €42,000: €6,000 accessible reserve, €8,000 cash for a bill in 12 months and €28,000 long-term. Income €2,400 minus spending €2,100 currently leaves €300 monthly. Its long-term goal is flexible, but its amount and price basis are not yet recorded.
Compare 20/80 and 70/30 shares/bonds when shares fall 20% and bonds stay unchanged. At the same time, income becomes €2,100 and spending €2,300 for four months; contributions can stop before the next transfer. Ignore interest, inflation, costs, tax and currency changes. Provider withdrawal timing is unchecked.
Calculate each portfolio and the household cash gap. Explain a difference between the structures, keep the bill money assigned and name one fact to establish before relying on a sale. Which conclusion about long-term funding remains unavailable?
Compare the calculations and reasoning after your attempt
20/80 starts with €5,600 shares + €22,400 bonds; after the fall, €4,480 + €22,400 = €26,880, a €1,120 loss. 70/30 starts with €19,600 + €8,400; afterwards €15,680 + €8,400 = €24,080, a €3,920 loss.
Pausing contributions leaves €2,300 − €2,100 = €200 monthly spending gap. Four months use €800 of reserve, leaving €5,200; the bill’s €8,000 stays assigned. The unused €300 transfer is not spare income in this changed budget.
A reasoned comparison can favour different trade-offs, but must keep the money assigned once, use the same shock and separate known facts from assumptions. Ask the provider about actual withdrawal restrictions and settlement/payment timing before a required sale. Neither structure’s result establishes whether the long-term goal is funded: its amount, price basis, date and future additions need recording. Do not fill the missing facts with a return assumption.
A planned income change needs a different funding path.
This separate fictional household plans part-time work after year six. Its nearby payment is already funded; its flexible long-term project must fit two contribution phases. Follow what changes in the money before comparing its finished note with the first household’s.
- 1 · €12,000 reserveAccessible cash for interruptions
- 2 · €18,000 fixed billNominal euro payment in month 9; separately funded
- 3 · €48,000 portfolioOnly this boundary receives share/bond weights
- Known now
- No debt. Income €3,100 − spending €2,850 = €250 monthly. Long goal: a flexible €75,000 in today's euros in 12 years.
- Scenario estimates
- After year 6: part-time income €2,800 − spending €2,650 = €150 monthly, in today's prices. Future budgets, investment results and interruption duration remain assumptions.
- Now€48,000 invested
- Months 1–72€250 at each month-end
- Months 73–144€150 at each month-end
Both phases keep constant purchasing power; nominal transfers must rise with prices. That affordability needs checking. All results below use today's euros on a common €0–€100,000 scale; dashed line: €75,000 goal.
-2% real annually€62,875 · €12,125 short
0% real annually€76,800 · €1,800 above goal
+2% real annually€93,841 · €18,841 above goal
Constant effective real rates, net of investment costs; personal tax omitted. These are sensitivity assumptions, without probabilities or a return assigned to any mix.
Check the two-phase calculation and price basis
For annual effective real rate r, use monthly factor q = (1 + r)^(1/12). After 144 months the balance is €48,000 × q^144 + €250 × (q^72 − 1)/(q − 1) × q^72 + €150 × (q^72 − 1)/(q − 1). Each addition arrives at month-end. The first phase’s ending balance continues compounding throughout the second.
At zero return: €48,000 + 72 × €250 + 72 × €150 = €76,800. Using €250 for all 144 months would give €84,000, overstating additions by €7,200. The −2% and +2% cases end at about €62,875 and €93,841.
These are today’s euros. If the project’s price separately rises 2% annually, €75,000 today would cost about €95,118 future nominal euros in 12 years. That converts units; do not add it to a real result. The feasibility of inflation-adjusted transfers and the part-time budget needs checking before relying on either phase.
Compare the loss and the work it leaves.
Shares −25%; bonds −8%. Both tracks use €0–€48,000. The same share/bond boundary stays in place: solid parts remain, outlined parts show each asset’s loss. No flows, costs, tax or currency change. S = shares; B = bonds.
20/80 shares/bonds
Before: S €9,600 + B €38,400 = €48,000
Before
After · losses stay inside their original asset boundaries
Share loss €2,400; bond loss €3,072.
After: S €7,200 + B €35,328 = €42,528
Loss €5,472. Under shares +20%, bonds +2% instead: €50,688.
50/50 shares/bonds
Before: S €24,000 + B €24,000 = €48,000
Before
After · losses stay inside their original asset boundaries
Share loss €6,000; bond loss €1,920.
After: S €18,000 + B €22,080 = €40,080
Loss €7,920. Under shares +20%, bonds +2% instead: €53,280.
80/20 shares/bonds
Before: S €38,400 + B €9,600 = €48,000
Before
After · losses stay inside their original asset boundaries
Share loss €9,600; bond loss €768.
After: S €28,800 + B €8,832 = €37,632
Loss €10,368. Under shares +20%, bonds +2% instead: €55,872.
The opposite event changes the comparison. Neither event is a loss limit, forecast or proof that a weight funds the goal.
For this exercise, the household carries 20/80 forward. It accepts the smaller result in the favourable event in exchange for less reduction of long-term capital in the adverse one. The 50/50 and 80/20 structures have a different price for greater share exposure. Neither the twelve-year horizon nor this comparison identifies one uniquely correct weight.
Pause the €250 transfer before month 1. Income €1,900 − spending €2,850 leaves €950 to fund each month.
- Before event€12,000 reserve
- End of month 1€11,050 reserve€950 withdrawn for spending
- End of month 2€10,100 reserve€950 withdrawn for spending
- End of month 3€9,150 reserve€950 withdrawn for spending
€18,000 bill cash stays assigned. This €2,850 operating gap needs no portfolio sale in the stated event. Three missed additions also remove €750 from long-term funding.
Only if the budget recovers: no additions in months 1–3, then 69 × €250 and 72 × €150 at month-end. Reserve stays €9,150; no replenishment is included.
20/80: €42,528 + €28,050 additions = €70,578
50/50: €40,080 + €28,050 additions = €68,130
80/20: €37,632 + €28,050 additions = €65,682
The short cash calendar omits price changes, interest, costs and tax. It makes no claim about preserving cash purchasing power for 12 years.
Even 20/80 now leaves €4,422 missing against the €75,000 goal in that zero-real-return continuation. Keeping the goal would require a new funding source or a recalculated date; the ordinary budget already uses its entire surplus. The household conditionally reduces the optional project’s scope to €70,000 in today’s euros, keeping the date and 20/80. Its €578 margin is small and does not fund the goal under every other assumption.
Check the continuation before calling the goal funded
For 20/80, €42,528 + 69 × €250 + 72 × €150 = €70,578 at 0% real after the immediate shock. To close the original €4,422 gap over the remaining 141 payments at that rate would require about €31.37 extra per payment. The present budget supplies no such extra money.
Delaying or revising the project is another branch; no recovery date has been established. The €70,000 revision does not cause 20/80 to become optimal. The reserve is now €9,150, whose adequacy for another interruption needs review. Resuming the original contribution schedule is an explicit assumption about a recovered budget. If additions replenish the reserve instead, subtract them from long-term funding and recalculate.
Price the implementation, then write the conditions.
Two fictional arrangements below supply the same 20/80 exposures and currency treatment, without borrowing. The household conditionally records mixed fund M to delegate weight maintenance during the part-time transition, accepting its higher stated cost. Separate funds remain an alternative for someone prepared to do that work. The fee difference alone cannot decide the arrangement.
Fictional document extract and first-year cost comparison
- Mixed fund M
- 20% broad shares / 80% bonds. Fund charge 0.35%; account charge 0.10%. Orders included for this exercise. Fund policy maintains the weights.
- Separate share S and bond B funds
- Same underlying exposures and currency treatment. Fund charges S 0.20%, B 0.10%; weighted charge 0.12%. Account charge 0.10%; two first-year orders at €4 each. Household maintains the weights.
- Access and legal terms · both routes
- Provider confirmation missing. Exact class/claim, withdrawal terms, documents and applicable local restrictions need checking before purchase or payment reliance.
On a fixed €48,000 base, M costs €168 + €48 = €216. S/B costs €57.60 + €48 + €8 = €113.60. The €102.40 difference accompanies different delegated work. Compare each route’s own costs; these alternatives are not held together.
This fixed base simplifies comparison; actual charges depend on balances, orders and terms. The earlier assumed returns were already net of investment costs: do not deduct these fees again. The extract establishes no legal eligibility or guaranteed withdrawal time.
- Goal and boundary
- Conditional €70,000 real project in year 12; €48,000 original investment boundary. Reserve and €18,000 month-nine bill remain separate assignments.
- Choice and funding
- Keep 20/80 for the stated adverse/favourable trade-off; provisionally use M for delegated maintenance. Funding after the event assumes the budget recovers and the €250/€150 real schedule resumes; reserve remains €9,150.
- Maintenance
- Fictional quarterly check: 20% shares target; 15–25% share band, measured in percentage points. Confirm roles and capacity first, then examine available contributions and costs before restoring. Review the full budget and funding annually, before year six and after material income, expense or access changes.
- Open work before reliance
- Verify inflation-adjusted contribution feasibility and the current budget before resuming transfers; confirm purchase/payment access and exact terms before relying on either; establish the actual part-time budget before year six ends. Any diverted or missed additions require a new funding calculation.
This is a complete chain of reasoning with an unresolved condition. A decision can be recorded while its next action remains blocked by missing evidence.
What can you establish from an incomplete record?
- Cash statement · known now
- €54,000 available; €9,000 assigned to reserve.
- Tuition invoice
- $12,000 due in month 4.
- Illustrative conversion quote
- $1.20 for €1; not locked. Fee: 1% of the converted euro principal, added to the euro debit.
- Expected receipt · unconfirmed
- €5,000 in month 5; amount and date unconfirmed.
- Current monthly budget
- Net income €2,600; regular expenses €2,350. Annual insurance €600 is excluded from those expenses. Its due date and existing provision are not recorded.
- Long goal
- €60,000 in today's euros in 8 years. Flexibility not recorded.
- Provider note
- “A displayed balance may be available for trading before it can be withdrawn.” Withdrawal timing and bank payment cutoff are not supplied.
- Euro principal + conversion fee
- Currency holding/conversion terms
- Withdrawable money
- Bank route and cutoff
- $12,000 received by month 4
Before opening the discussion, draft a conditional note. Keep the figures and unknowns together in your own working copy.
- At $1.20/€1
- Euro principal ___ + fee ___ = debit ___; remainder after reserve ___
- At $1.00/€1 instead
- Debit ___; remainder ___; shortfall against first assignment ___
- Contributions
- Surplus after annual-bill provision ___; nearest premium funded? ___
- Before relying on access
- Missing fact ___; source ___; deadline ___
Separate known facts, estimates and unconfirmed money. Compare keeping the available remainder accessible until the currency payment with setting aside only today’s calculated euro debit. State when the latter would leave the invoice short. Name at least two missing facts, where to check them and the deadline before relying on the answer. You may leave the long-term allocation open: the incomplete goal, funding and access record supplies no required mix.
Compare a conditional note after your attempt
At $1.20/€1, $12,000 requires €10,000 principal plus €100 fee: €10,100 debit. After the €9,000 reserve assignment, €34,900 remains. At $1.00/€1 instead, €12,000 + €120 = €12,120, leaving €32,880; the earlier euro assignment is €2,020 short. These are conditional quotes, with no stated probability or exchange-rate limit. Neither remainder is established as finally free to invest.
Keeping the remainder accessible preserves room to fund a changed euro debit but delays long-term investment exposure; it does not remove currency risk. Setting aside only €10,100 and committing everything else can leave the invoice unfunded if conversion becomes more expensive. Check actual conversion and holding terms before choosing: no dollar account, hedge or cost-free conversion has been established. Holding euros accessible also does not itself settle the dollar invoice.
The apparent €250 monthly surplus excludes insurance. If even provision is feasible and there are no other expenses, €600/12 = €50 monthly leaves a €200 contribution ceiling. The next premium’s due date and existing provision remain unknown; monthly saving does not establish that the nearest bill is already funded.
The unconfirmed €5,000 expected in month five cannot pay the month-four invoice or be added to €54,000 available now. Confirm its amount and date with the payer. Before relying on the payment plan, establish the final invoice amount, accepted route and cutoff with the issuer; establish fee scope, conversion/holding and withdrawal terms with the provider. Check the insurance due date and existing provision, other annual bills, and the long goal’s flexibility and price basis before assigning the remainder.
- Assignments. Give each euro at most one job. Reserve, bill cash and portfolio cannot fund two payments at once.
- Amounts and weights. Parts add to the stated boundary; weights use the current denominator. Distinguish flows from returns.
- Units. State the period, contribution/withdrawal timing, spending currency and real or nominal price basis.
- Assumptions. Separate facts, estimates and missing information. Scenarios supply neither probabilities nor a maximum loss.
- Consequences. Show money left, unfunded amounts, missed or redirected additions and payment dates. Name the cost of an alternative.
- Unfinished work. Ask a specific question; name the evidence and deadline before relying on its answer.
Use this to check internal consistency in the fictional exercises. It does not establish suitability of real holdings.
Different action sequences can satisfy the task. Keep dependencies visible; do not invent a provider answer, future return or personal allocation to close an unknown.
Keep a working copy with its assumptions.
Blank prompts to copy into your private note
- Goal
- Amount, date, currency, purchasing-power basis, priority and flexibility.
- Money included
- Capital/accounts included; reserves, restrictions and other goals excluded.
- Contributions
- Affordable amount, source, nominal/real basis and triggers for reducing or pausing it.
- Funding
- Several explicit assumptions, calculated endings and what can change if funding falls short.
- Investment mix
- Roles, compared weights, denominator, consequences and reason for the choice.
- Loss consequences
- A difficult market and household scenario, payments affected and feasible funding branches.
- Implementation
- Each holding’s purpose; identity, costs, country rules, provider checks and access.
- Maintenance
- Review dates, allocation bands, drift units, cash flows and adjustment costs.
- Attention and revision
- Routine tasks, security alerts and changes in goals, income, obligations, access or terms.
- Open work
- Missing facts, who or what can resolve them, next action and return date.
For “5% drift”, specify percentage points or change relative to a target. Link supporting records; leave “not checked” visible until the evidence answers the question.
Give unfinished work a deadline.
Date the draft and keep old and new versions with reasons for changes. Name the evidence and action needed before relying on a contribution, purchase or withdrawal. The next lesson’s six independent situations test an existing rule, a missing fact or a necessary amendment.