Phase Space AI

Trade Construction

TransMedics Group [TMDX]

TransMedics Group [TMDX] — Trade Construction

No position verdict is issued here. The memo scores Criteria and outputs an analysis. This document establishes what is implementable at book size and at what cost — the Liquidity Criteria — and constructs the vehicles the book would use if it allocates. It does not recommend one.

Nothing has been appended to trade_recommendations.jsonl. No position is recommended, so there is nothing to log.

Spot $76.35 (2026-07-28 close) · last trade $76.64 (2026-07-29 14:03 UTC) · analysis date 2026-07-29


1. Liquidity Criteria — BINDING — PASS

1.1 The underlying

Metric Value Source
Consolidated 63-day ADV $98.0m / 1,336,555 shares Alpaca SIP daily bars
Market capitalisation $2,638.7m 34,560,911 × $76.35
Realised volatility, 252-day 59.3% daily log returns
Realised volatility, 63-day 75.0% daily log returns
50-day MA / 200-day MA $71.70 / $109.62
Drawdown from 52-week high ($150.31) −49.2%
Drawdown from all-time high ($176.15) −56.7%

At $98m of daily consolidated turnover a position of any size this book would take is a fraction of one day's volume. PASS on the underlying.

A data caveat that matters and is disclosed: the Alpaca IEX feed reports 63-day ADV of only $4.3m — IEX prints roughly 2–4% of consolidated tape. Any liquidity figure taken from the IEX feed would understate TransMedics' tradability by ~23×. The SIP figure above is the one used. This is recorded because the same substitution would silently fail the Liquidity Criteria on a perfectly liquid name.

1.2 The options chain — pulled, not assumed

Per the Criteria, "any proposed options structure requires the actual chain pulled first." Full chain pulled from Alpaca on 2026-07-29: 168 contracts across five expiries (2026-08-21, 09-18, 10-16, 12-18, 2027-01-15), 140 with live snapshots.

Expiry Total open interest (strikes $50–$140)
2026-08-21 no live snapshots returned — not usable
2026-09-18 612
2026-10-16 9,951 (concentrated: 6,027 in the $100 call alone)
2026-12-18 6,256
2027-01-15 8,361

PASS. This is not the HCA failure mode (18 contracts of maximum OI across an entire chain). Quoted sizes at the liquid strikes run 50–226 contracts a side.

But the chain is expensive, and that is the operative finding.

Implied volatility, Jan-2027 at-the-money region 72–77%
Realised volatility, 252-day 59.3%
IV / RV(252d) ~1.25×
Realised volatility, 63-day 75.0%
Typical bid/ask as % of mid, Jan-27 $85 call (11.13 / 14.13) 24%

Implied vol is a quarter above one-year realised, and the quoted spreads are 15–25% of mid. Buying naked premium here is paying twice — an elevated vol level and a wide crossing cost — six days before the event that would collapse it. Any structure should be short some premium against long premium, or the exposure should be taken in stock.


2. Vehicles, if the book allocates

Prices are live bid/ask at 2026-07-29. All spreads are priced at the adverse side of both legs (pay the ask, hit the bid) — no mid-market fills are assumed.

2.1 Stock

The cleanest expression. Realised vol is 59%; inverse-volatility sizing handles the tail, which is what the framework relies on in place of a binding downside cap.

2.2 Defined-risk call spread — the vehicle that is actually fillable and vol-neutral

Jan-2027 $85 / $125 call spread

Leg Strike Action Price used OI Quoted size Delta IV
Long $85.00 call buy at ask 14.13 469 186×161 +0.530 74.3%
Short $125.00 call sell at bid 3.28 1,761 18×30 −0.245 74.1%
Net debit $10.85 +0.285
Maximum value at expiry $40.00
Maximum profit $29.15 per share (269%)
Maximum loss $10.85 (100% of premium)
Breakeven $95.85 (+25.5% on spot)
Payoff ratio 2.7 : 1
Expiry 16 Jan 2027 — 171 days, capturing Q2-26 (4 Aug), Q3-26 (late Oct) and the FY2026 guide-setting print

Why this structure and not a naked call: the short $125 leg finances 23% of the debit and, at 74% IV, sells back most of the vol premium being bought. The strikes bracket the valuation output — $85 sits just above the "no re-rating" target of $98's lower support and below the base target of $122; $125 sits just above the base target, so the structure is calibrated to the base case rather than to the bull case.

Fill reality: the short leg quotes 18 up / 30 down. A book taking size would need to work the $125 leg or step to the $120 strike (OI 966, 18×54) or $130 (OI 150, 28×49). This is a workable chain, not a deep one.

Q2 2026 prints 4 August 2026 after close — 6 days out. September-2026 at-the-money IV is 76–79%, i.e. above the already-elevated Jan-27 term. Buying the event through options means paying a crush that is essentially certain to occur on 5 August. If the book wants event exposure it should take it in stock, or wait until after the print, when the same Jan-27 structure will be available at a lower vol level.

2.4 Downside hedge, priced

Dec-2026 $60 put — bid 5.50 / ask 8.05, OI 198, quoted 104×126, IV 82.5%, delta −0.226. At the $8.05 ask it costs 10.5% of spot for 21% out-of-the-money protection to December. Against the downside case of $63 (−18%), the hedge barely pays. The protection is not worth its price at this vol level — which is itself a statement about how much downside the option market has already priced.


3. Sizing inputs (the book decides the size; these are the inputs it needs)

Input Value
Realised volatility, 252-day 59.3% — HIGH tier
Realised volatility, 63-day 75.0% — deteriorating
Valuation Criteria margin +9.5pp at base; +4.1pp at a mix-honest terminal margin; FAIL below 12.6%
Named permanent-loss cause Somerville $374.6m purchase option (by 31 Dec 2027) + $460m converts (1 Jun 2028) vs $461.7m cash
Bear / severe targets $63 (−18%) / $39 (−49%)
12-month base target $122 (+60%)
Concentration single organ (liver, 76% of revenue), single country (US, 96.6%), single reportable segment
Correlation note a device name with a 38%-of-revenue charter-aviation segment; fuel and pilot-labour exposure is not shared with any medtech comparator

Two things a sizing rule should be told explicitly:

  1. Volatility understates this tail. Inverse-vol sizing is the framework's interim protection under the Downside Criteria, and it works because fat-left-tail names are usually high-vol names. Here the left tail is a financing event (a forced equity raise into a −49% stock), not a business event — and financing tails are not fully expressed in trailing realised vol. Size below what inverse-vol alone would give.
  2. The event is six days away. Any sizing decision taken on this memo is a decision to hold through a print whose numbers are not in this document.

4. Momentum Criteria — MEASURED — INDETERMINATE

12-1 momentum −41.3%
Spot vs 200-day MA ($109.62) −30.3%
Spot vs 50-day MA ($71.70) +6.5%
From 52-week high −49.2%
Cross-sectional percentile INDETERMINATE

The Criteria require momentum to be assessed cross-sectionally against a broad universe, not by absolute rules such as "above the 200-day." No universe momentum panel was available to this run, so the percentile cannot be computed and is recorded as INDETERMINATE. The raw figure above is reported but is not a substitute for the percentile and is not treated as one.

Momentum is MEASURED. It governs when to enter a position the thesis already justifies, never whether. It blocks nothing here.


5. Invalidation and monitoring

These are the observable events that would falsify the analysis, not price stops.

Trigger Where it appears What it invalidates
FY2026 revenue guidance cut below $727m Q2 print, 4 Aug 2026 The 21.2% demonstrated comparator. Below ~11.7% growth the implied-path test fails outright.
Operating margin below ~10% for a second consecutive quarter Q2 print The 19% terminal margin. At a 12.6% terminal margin the Valuation Criteria flips to FAIL.
Service (logistics) mix above 42% of revenue segment-expense table, each 10-Q The 59% blended gross-margin ceiling, and with it the terminal margin.
US liver revenue growth below ~20% YoY revenue-by-organ table, each 10-Q The single engine carrying the whole franchise.
Any equity issuance or new convertible 8-K / 10-Q The share count in the 12-month target, and the downside case's central mechanism.
ICFR material weakness not remediated at FY2026 year-end FY2026 10-K, ~Feb 2027 Third consecutive year. The product-margin series, which is the memo's core exhibit.
HRSA action on allocation-out-of-sequence OPTN/HRSA publications The NOP volume engine. Currently unquantifiable.
Somerville purchase option abandoned 10-Q lease note Would improve the balance sheet (required CAGR 11.7% → 9.0%) at the cost of a $334.5m ROU writedown.

6. What this document does not establish

  1. No position is recommended and nothing is logged to the ledger.
  2. Option prices are a single snapshot taken 2026-07-29 during market hours, six days before an earnings event. They will not hold.
  3. All spread economics are quoted at the adverse side of both legs. Real fills may be better; they are not assumed to be.
  4. The capped calls are ignored in every share count, as in the valuation.
  5. The momentum percentile is INDETERMINATE, not zero and not "poor."
  6. No borrow, short interest or days-to-cover data was pulled. Those are not part of the Liquidity Criteria on a long-only book, and the relative-value fork is not run here.