Decomposing a fall into its temporary causes, testing a monopoly by asking whether it could be rebuilt, and reading a target price backwards to find the assumptions doing the work.
1. Before buying a fallen compounder, decompose the decline into named, dateable causes
The repeatable method
- Establish first that the fundamentals fell, not just the price — falling revenue and profit is a different problem from a falling multiple.
- List every distinct cause you can name, and label each one temporary or structural.
- For each temporary cause, say what specifically reverses it and roughly when the comparison base stops being distorted.
- Check whether the causes are independent or one event in three costumes — several unrelated headwinds landing together is the case for "temporary"; one cause described three ways is not.
- Ask what would have to be true for the decline to be structural instead, and look for that evidence explicitly.
Here: WSO is down over 45% from its peak with revenue and net income falling, and the fall is attributed to three simultaneous distortions: COVID pull-forward (demand borrowed from later years, plus dealer over-ordering that had to be worked through), the A2L refrigerant transition (supply-chain disruption that also temporarily boosted demand) and OEM pricing normalisation (post-pandemic price rises unwinding, having flattered both sales and margins). Each inflates the prior-year comparison rather than damaging the franchise. Step 5 is not run: no evidence is sought that could show the decline is structural.
Watch for
- Three causes that are really one — a pandemic demand spike, dealer overstocking and post-pandemic price rises are all downstream of the same event.
- No date. "Temporary" is only useful with a horizon; without one it is indistinguishable from hope.
2. Test a monopoly by asking what it would cost to rebuild it today
The repeatable method
- Ask literally: if a rival had unlimited capital, could they reproduce this asset? Price the land, the permits, the approvals and the time.
- Separate the physical barrier from the regulatory one; regulatory barriers can be repealed, physical ones usually cannot.
- Check the unit-cost advantage independently of the barrier — a protected asset that is also the cheapest way to do the job is protected twice.
- Confirm the pricing power that should follow: has it actually raised prices at or above inflation across cycles?
- Then separate the asset from the cycle it serves, and decide which one you are underwriting.
Here: CNR.TO — "the only railroad in North America connecting the Atlantic, Pacific, and Gulf coasts", where "because of the cost of land, zoning restrictions, and environmental permits, no new competitor will ever be built", trains "use 4x less fuel than shipping by truck", and rates have been raised "at or above inflation through different economic cycles." Step 5 is where the actual decision sits: "freight volumes have been falling for the past few years", so this is a cycle bet wearing a monopoly's clothes. TDG passes the same test through certification rather than geography — "for 80% of their products, they are the only certified manufacturer" — and MCO through regulation: "you need to have a rating from at least 2 of the 3 big players."
Watch for
- A monopoly on a shrinking activity. Owning all the toll booths on a road nobody drives is worth nothing.
- Regulatory moats being regulatory risks in the other direction — rating agencies and sole-source suppliers with pricing power are recurring political targets.
3. Read a target price backwards and count how many of its inputs you supplied yourself
The repeatable method
- Write the target as an explicit chain: revenue × margin × multiple.
- Label each link — company guidance, consensus, or your own assumption.
- Flex the assumed links one at a time and see what survives. A conclusion that needs every optimistic input is not a valuation.
- Attach a date. An unspecified "by then" turns any upside into an unfalsifiable claim, because compounding at an unknown rate over an unknown period is not a return.
- Convert to an annualised return before comparing with anything else.
Here: WSO's only number. "Management has long-term targets of $10 billion in revenue and 30% gross margins. If we assume a 8% Net Profit Margin is realistic, this would translate into $800 million in Net Income. At a FWD PE of 25x, this means the company should be worth $20 billion… an upside potential of 56%." Revenue = management's target; margin = the author's assumption; multiple = the author's assumption; date = absent. Two of three inputs and the entire time axis are supplied rather than observed.
Watch for
- A 25x exit multiple used as though it were neutral. It is the same "fair exit PE" that anchors the earnings-growth model across the whole Buy-Hold-Sell sheet.
- Management's own long-term targets imported as facts. They are marketing until delivered, and "long-term" is doing a lot of work.
4. Take candidates from the losers list, and check the pipeline actually runs
The repeatable method
- Rank your pre-vetted universe by recent performance and read the bottom of the list first.
- Choose the spotlight from that bottom section, so the research effort is aimed where the price has already moved against consensus.
- Track which spotlights later become purchases and how long the lag is — the conversion rate is the honest measure of whether the shortlist is a pipeline or content.
- Watch the repeat offenders: a name appearing on the worst list two months running is either a compounding opportunity or a thesis quietly failing.
Here: "The cheaper we can buy great companies, the better." The worst list — Walker & Dunlop −19.9%, Judges Scientific −19.6%,
WSO −18.7%,
ROL −17.0%, Dick's −15.9% — supplies the spotlight directly. The pipeline's record is good:
July's #1 SPGI was bought seven days later and #2
FFH.TO four weeks later.
ROL is the repeat offender, on the worst list in both July and August, down 39% year-to-date, and still not on the 55-name Buy list.
Watch for
- The names that keep being screened and never bought. That residue is where the real filter lives.
- A universe narrow enough that the "worst performers" are simply the same handful of holdings each month.
5. Distinguish demand that is chosen from demand that is forced, and price the difference
The repeatable method
- For any distributor, supplier or service business, estimate what share of revenue is emergency or mandated rather than discretionary.
- Ask what the buyer optimises for in that moment. If it is speed or availability rather than price, the supplier holds the pricing power.
- Confirm the switching friction: certification, local inventory, workflow software, regulation.
- Treat that share of revenue as quasi-recurring and underwrite it separately from the cyclical remainder.
Here: WSO — "70%-80% of sales are emergency replacements & repairs… when something breaks down, the most important thing for contractors is how easily and quickly they can get the parts, not what they cost." The same test applied to TDG: "airlines cannot legally fly a $100M plane without certified parts", on aircraft in service 25-30+ years. And to MCO: a rating from two of three agencies is effectively compulsory before issuing debt. Three different industries, one structure — the buyer has no practical alternative at the moment of purchase.
Watch for
- The mirror risk: forced demand is a political target precisely because it is forced.
- Emergency share estimated by the company itself and quoted as a range ("70%-80%") — worth checking against segment disclosure.
6. Notice when a shortlist gives you quality with no price, and refuse to complete it yourself
The repeatable method
- For every recommendation, ask what the entry price is. If none is given, the recommendation is a description of a business, not a decision.
- Check whether the same source publishes prices elsewhere. If it does, the omission is a choice.
- Go and get the number from the source's own other work rather than inventing one.
- Only then decide, and record the price you used, so the call can be judged later.
Here: MA,
TDG,
MCO,
CNR.TO and
RMS.PA are ranked one to five with
no fair value, forward PE, expected return or reverse DCF between them — one week after the
Buy-Hold-Sell list published all three models for 55 stocks. The numbers exist and can be fetched: Mastercard at a 26.8 forward PE against a 32.6 average with a reverse DCF requiring 13.7% against 15% expected; Moody's at 27.6 against 32.7 with the DCF dissenting; TransDigm at 30.8 against 34.7 with a 7.2% "dividend yield" that is really lumpy special dividends; Hermès at 35.7 against 48.3 with the lowest expected return on the whole Buy list at 10.00%. Against the archive's own standard — "quality alone never triggers a buy" — this issue does not clear its own bar.
Watch for
- Business descriptions that read as buy cases. Every one of the five paragraphs would be equally true at twice the price.
- Your own tendency to supply the missing valuation charitably. If the writer did not do it, do it adversarially or not at all.
7. Separate a currency-driven slowdown from a demand-driven one before treating a de-rating as opportunity
The repeatable method
- Find the constant-currency growth rate alongside the reported one; the gap is translation, not trading.
- Check whether the currency move is also hitting costs — a manufacturer producing in the same currency it reports in is affected very differently from an importer.
- Ask whether the market has de-rated the multiple or only marked down the earnings; only the first is an opportunity.
- Confirm the demand signal independently — for a scarcity brand, the resale market is the cleanest read.
Here: RMS.PA — revenue and net income "slowed a little bit" in 2026 and the stock is down nearly 30%, but "much of the slower growth comes from currency headwinds. On a constant-currency basis, the underlying business is still growing." The independent demand check is supplied: "pre-owned bags often sell for more than new ones", which is a market saying supply is still short of demand. The family's 65%+ stake is the guarantee that supply will not be raised to fix a soft quarter.
Watch for
- "Constant currency" as a permanent excuse. Currencies trend for years, and a euro reporter with global sales lives with it.
- A de-rating from very expensive to less expensive being mistaken for cheap — the previous week's sheet still had the reverse DCF demanding 18.4% growth against 11.9% expected.
Methods distilled from the archived Compounding Quality post for personal study. Not investment advice.