Concept: most investors price the fund and forget to price the trade. Five lines, filled in before you press "buy" or "sell", show what a trade costs in dollars and how long the benefit takes to pay it back.
What This Resource Does
This check turns any switch, rebalance, or new purchase into one number: the years the trade needs to pay for itself. It covers:
- Line 1: commissions and platform fees
- Line 2: spread and any premium to net asset value
- Line 3: transaction taxes and currency conversion
- Line 4: tax triggered by selling what you hold
- Line 5: total cost, cost as a percentage, and break-even years
It is the quick version of the Tracking Difference True-Cost Estimator and the Rebalancing Drift Break-Even Test. Use it before any trade, however small.
Inputs You Need
| Input | Where to find it |
|---|---|
| Amount traded | Your plan |
| Commission and platform fee per trade | Broker fee schedule |
| Bid-ask spread of each fund | Broker quote screen, during normal trading hours |
| Premium or discount to NAV | Fund page or broker |
| Transaction tax or stamp duty, and FX charge | Tax authority, broker fee schedule |
| Cost basis and value of what you would sell | Brokerage statement |
| Tax rate on the gain, and whether the account is taxable | Your tax bracket, account type |
| Annual benefit of the trade (fee saving, risk reduction in dollars) | Your own calculation |
| Expected holding period | Your plan |
The Formulas
Line 1: Explicit fees
Fees = Commission and platform fee on every trade, buy and sell
Line 2: Spread and premium
Spread cost = Amount × (Half-spread on sale + Half-spread on purchase)
Premium cost = Amount × Premium paid over NAV
A half-spread is each fund's bid-ask spread ÷ 2.
Line 3: Transaction taxes and currency
Duties and FX = Amount × (Transaction tax on purchase + FX conversion charge)
Line 4: Tax on selling
Gain share = (Value − Basis) ÷ Value
Tax = Amount sold × Gain share × Tax rate
This is zero inside a tax-sheltered account, subject to local rules.
Line 5: Total, percentage, and break-even
Total cost = Line 1 + Line 2 + Line 3 + Line 4
Cost % = Total cost ÷ Amount
Break-even years = Total cost ÷ Annual benefit
Decision rule
Trade if Break-even years ≤ Holding period ÷ 2
The halving leaves a margin for estimates that turn out wrong.
Fixed-fee check
Fee as % of trade = Fixed fee ÷ Amount
Minimum sensible trade = Fixed fee ÷ Cost % you will accept
Worked Example
Illustrative figures. You hold $40,000 in an older fund with a 0.80% annual cost and want to switch to an index fund costing 0.10%. You plan to hold for 10 years.
| Assumption | Value |
|---|---|
| Annual benefit | 0.70% × $40,000 = $280 |
| Commission | $10 per trade, two trades |
| Old fund half-spread / new fund half-spread | 0.05% / 0.02% |
| Premium to NAV | none |
| Transaction tax on purchase / FX | 0.10% / none |
| Basis of the old holding | $28,000 (value $40,000) |
| Tax rate on gains | 15% |
The Five Lines
| Line | Working | Taxable account | Sheltered account |
|---|---|---|---|
| 1. Fees | $10 + $10 | $20 | $20 |
| 2. Spread and premium | $40,000 × (0.05% + 0.02%) | $28 | $28 |
| 3. Duties and FX | $40,000 × 0.10% | $40 | $40 |
| 4. Tax on selling | Gain share 30%; $40,000 × 30% × 15% | $1,800 | $0 |
| 5. Total cost | $1,888 | $88 | |
| Cost % | 4.72% | 0.22% | |
| Break-even years | Total ÷ $280 | 6.7 years | 0.31 years (about 4 months) |
Applying the Decision Rule
Holding period ÷ 2 = 5 years.
| Account | Break-even | Rule | Result |
|---|---|---|---|
| Taxable | 6.7 years | Above 5 | Fail |
| Sheltered | 0.31 years | Below 5 | Pass |
If You Were Going to Sell Anyway
If the tax on this gain would be due eventually, Line 4 only brings it forward. The true cost is the growth you lose on the $1,800 paid early, not the whole $1,800.
Cost excluding Line 4 = $88, so break-even = $88 ÷ $280 = 0.31 years
Treat the $1,888 as the conservative case and the $88 as the optimistic one. The truth lies between them and depends on how long you would otherwise have held the old fund.
Cheaper Routes to the Same Switch
| Route | Total cost | Break-even |
|---|---|---|
| Sell everything now, taxable account | $1,888 | 6.7 years |
| Sell inside a sheltered account | $88 | 0.31 years |
| Send new contributions to the new fund and stop adding to the old | about $60 (fees and spread only) | under 0.3 years on the amount moved |
| Sell only the highest-basis lots first | lower Line 4 | depends on lots |
Fixed Fees on Small Trades
| Trade size | $10 commission as % | Verdict at a 0.25% limit |
|---|---|---|
| $500 | 2.00% | Too small |
| $2,000 | 0.50% | Too small |
| $4,000 | 0.25% | Borderline |
| $10,000 | 0.10% | Fine |
Minimum sensible trade = $10 ÷ 0.25% = $4,000
Verdict
- Taxable account: the switch costs about $1,888 and takes about 6.7 years to pay back. It fails the rule for a 10-year hold, so redirect new money instead.
- Sheltered account: the switch costs about $88 and pays back in about 4 months. Do it.
- Small trades: a $500 trade carries a 2% fixed-fee cost, so batch purchases or use a fee-free route.
How to Read It
- Line 4 is usually the biggest. In the example, tax was $1,800 of the $1,888. Check account type and lot choice first.
- The benefit must be a real dollar figure. Use the fee saving or risk removed from your own calculation, not a hoped-for return.
- Costs are certain and benefits are estimates. That is why the rule uses half the holding period.
- Spreads move. Check them during normal trading hours, and use a limit order.
- Round trips double the cost. A trade you may reverse needs the break-even to hold within a shorter horizon.
- Crypto and property use the same five lines. For a crypto sale, Line 2 is slippage, Line 3 is network fees, and Line 4 is capital gains. For property, Line 1 is agent and legal fees and Line 3 is transfer tax.
Step-by-Step Method
- Write down the amount and the annual benefit of the trade.
- Fill in Line 1 from your broker's fee schedule.
- Fill in Line 2 from live quotes for both funds.
- Fill in Line 3, including any purchase tax or FX charge.
- Fill in Line 4, using the highest-basis lots if selling from a taxable account.
- Add the lines to get total cost and cost % (Line 5).
- Divide total cost by annual benefit to get break-even years.
- Apply the decision rule against half your holding period.
- If it fails, test a cheaper route: a sheltered account, new cash, or a smaller trade.
- Record the result and the date.
Five-Line Worksheet (Copy This)
| Line | Item | Your figure |
|---|---|---|
| A | Amount traded | |
| B | Annual benefit of the trade (dollars) | |
| 1 | Fees: commissions and platform fees, all trades | |
| 2 | Spread and premium: A × (half-spreads + premium) | |
| 3 | Duties and FX: A × (transaction tax + FX charge) | |
| 4 | Tax on selling: A × gain share × tax rate | |
| 5a | Total cost (1 + 2 + 3 + 4) | |
| 5b | Cost % (5a ÷ A) | |
| 5c | Break-even years (5a ÷ B) | |
| C | Holding period ÷ 2 | |
| D | Pass? (5c ≤ C) | Yes / No |
| E | Cheaper route tested |
Pre-Trade Checklist (Copy This)
| # | Check | Done |
|---|---|---|
| 1 | Wrote down the annual benefit in dollars before looking at costs | ☐ |
| 2 | Included commissions on both the sale and the purchase | ☐ |
| 3 | Checked spreads on both funds during normal trading hours | ☐ |
| 4 | Checked premium or discount to NAV | ☐ |
| 5 | Checked transaction tax and FX charges | ☐ |
| 6 | Calculated tax on selling, and checked whether a sheltered account can do the trade | ☐ |
| 7 | Chose the highest-basis lots if selling in a taxable account | ☐ |
| 8 | Calculated break-even years and applied the half-holding-period rule | ☐ |
| 9 | Considered redirecting new contributions instead of selling | ☐ |
| 10 | Used a limit order, not a market order | ☐ |
| 11 | Checked wash-sale or similar rules if I plan to rebuy | ☐ |
| 12 | Recorded the decision | ☐ |
Common Mistakes This Check Catches
- Pricing the fund and not the trade. A cheaper fund still has to repay the cost of getting into it.
- Forgetting the tax on selling. It is often 90% or more of the cost.
- Counting only the commission. Spread, duties, and FX can exceed it.
- Trading small amounts with fixed fees. A $10 fee on $500 is a 2% cost.
- Using a hoped-for return as the benefit. Use a fee saving or risk figure you can calculate.
- Ignoring the cheaper route. New cash and sheltered accounts avoid Line 4.
- Trading at the open. Spreads are often widest then.
- Switching repeatedly. Each trade restarts the break-even clock.
Important Note
Commissions, spreads, transaction taxes, FX charges, and tax on gains differ by country, broker, and account type, and they change over time. The fees, rates, and holding periods above are illustrative, not forecasts, and the example ignores inflation, tracking difference, and growth on the tax paid early. This is a framework for pricing a trade, not personal investment or tax advice. Readers should check current fee schedules and consult a qualified financial adviser or tax professional.
%20Returns%20in%202026.png)
0 Comments