Phase Space AI

Trade Construction

iRhythm Technologies [IRTC]

iRhythm [IRTC] — Trade Construction & Liquidity Criteria

No position verdict is issued here.

1. Liquidity Criteria — PASS (equity), FAIL (options at any size)

Equity liquidity is adequate. Note the small share count (32.9m) — a large position is a meaningful percentage of the float, and the $650.3m converts are a potential future share-count event (see §3).

2. Vehicle ladder — rung 1, EQUITY

Chosen vehicle: common equity. Ladder position 1. No argument required.

Required disclosure, whatever the vehicle

Implied volatility minus trailing realised volatility, as a number:

Quoted size at the specific strike — this is the disqualifying measurement:

Why the answer is equity, on three independent grounds

1. A vehicle that cannot be filled is not a vehicle. Quoted depth at the ATM strike is 9 × 13 contracts — nominally ~$110k–160k of underlying exposure. This reproduces the HCA (18 contracts) and GMED (13 contracts) failure mode exactly. Chain-level open interest is equally thin: the entire Jan-2027 call chain peaks at 50 contracts (at the $175 strike), Feb-2027 peaks at 0, Mar-2027 at 2. Chain depth is not strike depth, and here neither is present.
2. Horizon conflict, named rather than silently resolved. Jan-2027 is 5.5 months out — shorter than the declared 12-month thesis horizon, so it sits on rung 3 and would require a catalyst before expiry. The catalyst that matters (CY2027 PFS final rule, ~1 Nov 2026) does precede a Jan-2027 expiry, so the catalyst test would pass — but the constructability test fails outright, and no longer expiry exists with any depth. Per criteria.md: "Where no expiry is both liquid and long enough, the answer is equity."
3. The premium. +9.9 points of implied over realised, plus a 22.8% round-trip spread at the strike.

Multi-leg (rung 4) is unconstructable. A Jan-2027 vertical would need a short leg at a higher strike; the deepest strike in the chain quotes ~50 contracts of open interest and single-digit quoted size. This is the FCEL failure (12-contract short leg) rather than the TE failure (constructable but capped where the thesis pays).

3. The convertible notes — a share-count consideration the vehicle choice must respect

$650.313m carrying value of senior convertible notes sit ahead of the equity. Interest expense is $3.290m/quarter (~$13.2m/yr, ~2.0% cash coupon), so there is no funding cliff. But:

• Against 32.854m shares, conversion is a material dilution event. The conversion price was not extracted from the filings in this run and is therefore not asserted — it is a named open item, not an estimate.
• The relevance to the vehicle: a long call position would be exposed to conversion-driven dilution capping the upside, on top of an unfillable chain. Equity at least participates in the same economics as the converts' reference security.
• The Valuation section's net-debt figure (−$100.7m) uses carrying value, not the if-converted share count. Stated so the basis travels with the number.

4. Position construction, if the book elects one

The Valuation Criteria returns FAIL on the 5-year implied path, while the 12-month target is +40.8%. That is a genuine horizon split, not a contradiction, and the book — not this memo — resolves it.

• Entry discipline: the dominant dated event is the CY2027 PFS final rule (~1 Nov 2026). Entering ahead of it is a bet on a rate outcome; entering after it removes the largest single variance source. Given the rate has just risen 7.8% and CMS has proposed a further increase for CY2027 (reported, not verified — see Catalyst Calendar), the skew is arguably favourable, but it is a policy coin-flip and should be sized as one.
• Invalidation gap: a CY2027 final rule cutting 93247 materially, or any DOJ escalation from CID to complaint/intervention, invalidates the thesis. Both are observable and dated.
• Sizing input: inverse-volatility at 43.9% realised vol places IRTC in a mid-size bucket — larger than DOCS's (57.0%). This is the wrong answer and the reason must be recorded: IRTC carries a genuine fat left tail (FCA treble damages plus per-claim penalties, and net debt) that 43.9% vol does not capture, while DOCS's left tail is cushioned by $748.6m of net cash. This is the HALO defect precisely — inverse-vol sizing mispriced a fat left tail at only 30% vol. IRTC should be sized below what inverse-vol prescribes, and the override should be explicit in the book rather than applied through a hidden haircut to the valuation (valuation.md rule 5: uncertainty reduces position size, never the operating assumption).
• Exposure tags: sub-sector MedTech (cardiac diagnostics). No overlap with DOCS (HCIT), so the two names in this pair do not compete on a concentration limit — but IRTC does correlate with the covered diagnostics complex (TEM, NTRA, GH, WGS) through the shared reimbursement-policy factor, which is a correlation the book should treat as a single risk rather than four.

5. Short Mechanism Criteria (MEASURED)

Neither leg present. Growth accelerating (20.3% → 25.7% on the Q1 comparison); margin runway abundant (operating margin −8.1%, gross margin 70.9%, SG&A 68.2% of revenue with 7.4pp/yr of demonstrated leverage). There is no short mechanism here. Recorded.