Lesson 1 of 8
From a reading to a rail
The whole move in one page. A statement about which liabilities are load bearing becoming a figure, a direction, a level and a date it is next checked.
By Javier Sanz
Founder of ValueScreener. Built Ninety Nine, a securities services provider, and sold it to a tier-one global bank; ran operations and internationalization at Alpaca, the brokerage API.
Who writes thisEditorial processLinkedIn (opens in a new tab)X (opens in a new tab)
In one minute
- A rail is a figure, a direction and a level, plus a date on which the next evidence arrives.
- The reading supplies the figure. The reason you hold supplies the level. Neither supplies the other.
- A reading that cannot be written as a rail has not finished, and usually it was a market opinion.
Four courses of balance-sheet reading produce one thing. This lesson is the conversion, and it is short because the move is small once the reading is done.
The four parts of a rail, and where each comes from
- 1The figureFrom the credit reading: which line is load bearing at this company
- 2The directionFrom the figure: stays at or above, or stays at or below
- 3The levelFrom the reason you hold: the point at which that reason has failed
- 4The dateFrom the filing calendar: when the next evidence exists
The figure comes from the reading
This is the only part the bridge supplies, and it is the part most readers get wrong by skipping. The reading answered which line decides at this company: a maturity year, a cushion measured from cash generation, or a margin whose cost base is mostly fixed.
Choosing the figure before doing the reading means choosing the figure everybody uses, which at some companies does not exist and at others answers a different question.
The level comes from the reason, not from the history
The thesis course states this and it is worth repeating because it is the most common failure: a level picked a little below where a figure has been will almost never be breached, so it confirms rather than tests.
The level is derived. State the reason in one sentence, work out what has to be true for it to hold, and compute the point at which it has demonstrably started to fail while something is still left of it.
The direction is mechanical
ValueScreener stores a condition as the assumption holding: at or above, at or below, above, below. Operating cash flow to debt stays at or above 0.60 means the assumption holds while the figure is at or above 0.60, and it is breached when it stops being true.
That phrasing matters when the figure can be negative. A condition written as stays above zero on a figure that is routinely negative in a trough is a condition that will fire in every trough, which may be exactly what you want, provided you knew.
The date comes from the filing calendar
Four known dates a year: the annual filing 60, 75 or 90 days after fiscal year end by filer status, and three quarterly filings 40 or 45 days after each of the first three quarters. The fourth quarter has no filing of its own.
That is the whole schedule. Between those dates there is nothing to do, which is the point of writing the rail rather than watching the company.
What it means if the conversion fails
If a reading will not convert, it was not a reading. The most common cause is that it contained a view about conditions rather than about the company, and those have no figure attached because they were never about one.
Check yourself
Where does the level come from?
- From where the figure has been over the past few years
- From the reason you hold, worked out to the point at which that reason has demonstrably started to fail
- From the peer group median
Show the answer
Answer: B.
A level set a little below the history will almost never be breached, so it confirms the reason instead of testing it.How is a condition stored here?
- As the event that would trigger it
- As the assumption holding, so at or above 0.60 means the assumption holds while the figure is at or above 0.60
- As a range with an upper and lower bound
Show the answer
Answer: B.
The assumption is breached when it stops being true. That phrasing matters most on figures that can go negative.A reading will not convert into a figure, a direction and a level. What does that usually mean?
- The company does not file enough detail
- That it contained a view about conditions rather than about the company, so there was never a figure attached
- That the figure needs to be computed by hand
Show the answer
Answer: B.
Some real conditions do have to be checked by hand, and the fifth lesson of this course writes one. That is different from a reading with no figure in it at all.Sources
- Micron Technology, Inc., annual reports on Form 10-K for the fiscal years ended 29 August 2024, accession 0000723125-24-000027, and 28 August 2025, accession 0000723125-25-000028, for debt, cash and operating cash flow.
- Form 10-K, General Instruction A(2), and Form 10-Q, General Instruction A(1), for the review calendar.
What this leaves out
- This is a heterodox tradition. The mainstream account of the same phenomenon differs, and nothing here is a forecast or a view on any security.
- The reason and the level in the worked example are written to show the derivation. They are not a condition anybody should adopt, and a different reason produces a different level from the same two filings.
- The filing deadlines are the outer bounds in the general instructions to the forms. A company may file earlier.
- Nothing here is a view on Micron or on any security.