Changing the ladder: the documented path from finding to production.

Why casual change is the enemy

An undocumented ladder edit poisons everything the ladder touches.

The prohibition on casual ladder changes isn't preciousness about a lookup table — it's protection for every record built on it. The audit loop grades coefficient decisions against outcomes, and the grading assumes the rung meant the same thing across the review window: silently nudge T4 from 1.85 to 1.95 mid-quarter and every T4 entry in the log becomes ambiguous evidence, the too-tight and too-wide signatures blur, and the next review grades a rung that was two rungs. The same corruption spreads to the trade record's coefficient fields and the MAE/MFE reads against them. It's the sandbox wall's logic at volatility scale: the change itself might even be right, and the ungoverned making of it still destroys the ability to know.

The legal path

Finding, proposal, Version Log, validation, then production.

The road a ladder change lawfully travels is short but mandatory at every step. It begins with an evidenced finding — the audit loop's review producing a rung signature, not a feeling after a bad week. The proposed adjustment is written with its evidence and rationale, and the Version Log entry is made: what changed, from what, to what, why, when — every change should be documented, the rule says, with no exception carved out for small ones, because small undocumented changes are how workbooks drift into unaccountability. Validation follows before live reliance: the changed values confirmed flowing correctly through the Coefficient Model, Comparison Panel, Dashboard, and Audit Log. Only then does the new rung price live trails — and the log's subsequent entries, tagged after the versioned change, begin accumulating the evidence that will eventually grade the change itself.

New instruments

Instrument Master first — a symbol earns its way in.

The same discipline governs expansion: if adding a new symbol, update the Instrument Master first and validate the bucket and coefficients before using it live. The ordering matters because a symbol's static classification is the anchor half of every future static-versus-VIE comparison — trade the symbol before the classification exists and the cockpit's comparison surface has nothing real to compare, the audit log's source field grades against a placeholder, and the profile keys begin accumulating samples under an unvalidated bucket. The entry sequence mirrors the change sequence deliberately: classify, validate, then trade — with the sample-status ladder then honestly reporting how young the new keys' baselines are for as long as they're young.

• Custom authority add-ons carry a note-why requirement; the default remains step difference × 0.50 unless documented otherwise.
• Consistency check after any authority-logic change: Control Panel, Coefficient Model, Comparison Panel, Dashboard, and Audit Log must all read the same final state.
• Static classification, dynamic radar, and VIE logic stay conceptually separate — the maintenance rules name the separation itself as a thing to preserve.

The coherence obligation

One authority state, read identically everywhere.

The final maintenance rule guards against the subtlest failure: partial change. When authority logic shifts, every surface must agree — a Comparison Panel computing against the new logic while the Dashboard displays the old is a workbook lying to its operator in one window and not the other, and decisions made across the disagreement can't be audited at all. The validation pass exists for exactly this: not just 'does the new value compute' but 'does every surface that touches this state now tell the same story.' It's the volatility layer's copy of the ecosystem's one-authority-system doctrine — coherence isn't a property workbooks have by default; it's a property maintenance discipline manufactures after every change, deliberately, and checks.

The key idea

Evolution through documentation is what keeps a calibrated system calibratable.

The volatility layer will change — markets guarantee it, and the audit loop exists to detect when. The change discipline guarantees something rarer: that after every change, the system can still explain itself. Every rung traceable to a versioned decision with its evidence attached; every symbol's classification validated before its first live trail; every surface agreeing about what the current truth is. That's the closing shape of the whole volatility category: a layer sophisticated enough to price chaos, governed carefully enough to never become it.