ARCT — Arcturus Therapeutics Holdings Inc.

Company context · prepared 2026-08-13 · company sweep 2026-08-13 · USD · framework v5.8.0

How to read this. Written for a reader who has not studied pharmacology or finance. General terms are defined once in framework/04-glossary.md. Tags: [VERIFIED — source] / [UNVERIFIED] / [WEB ESTIMATE — source, date].

Program analyses for this company are the sub-folders listed in C.2.

C.0 Company-tier coverage — CLEARED

One row per mandatory tool in the company-tier table in framework/02-connectors.md, in the order that file lists them.

Verdict: CLEARED. Every mandatory company-tier row was called and returned data. The three NOT CALLED rows are all marked optional in 02-connectors.md and so are not gate rows.

C.1 What the company is

Arcturus Therapeutics is a San Diego messenger-RNA company with two technology platforms: LUNAR, a lipid nanoparticle delivery system (a fatty bubble that carries genetic material into cells), and STARR, a self-amplifying mRNA design that makes more copies of itself once inside a cell [VERIFIED — BPIQ fetch_company_info 2026-08-13]. It runs two clinical rare-disease programs (ARCT-810 for ornithine transcarbamylase deficiency and ARCT-032 for cystic fibrosis) plus a vaccine portfolio built around KOSTAIVE, an approved COVID-19 vaccine.

It is not a single-asset company, and that changed materially eight days before this sweep. On 2026-08-06 Arcturus and CSL Seqirus terminated their vaccine collaboration; Arcturus regained global rights to KOSTAIVE and to the seasonal influenza, pandemic influenza, RSV and EBV vaccine programmes, took a one-time $12 million cash payment and was released from roughly $16 million of research-and- development credit liabilities [VERIFIED — Arcturus Q2 2026 press release, 2026-08-06].

It has revenue, but it is small and shrinking: $2.96 million in Q2 2026, against $82.0 million for full-year 2025 [VERIFIED — Q2 2026 10-Q summary and FY2025 10-K, via BPIQ press feed 2026-08-06 and 2026-03-04]. That revenue is collaboration and milestone income, not product sales the company books itself. Treat Arcturus as a clinical-stage company that happens to have a partnered approved product, not as a commercial one.

C.2 Pipeline — every program

Every row returned by fetch_company_drugs on 2026-08-13, including the failed one. Catalyst dates are reported as catalyst_date_text; the “to a day?” column is yes only where that text names a day (01-rules.md rule 23).

A caveat on the ARCT-032 row, stated rather than buried. BPIQ flags ARCT-032’s Q4 2026 Phase 3 decision as has_catalyst: false. The catalyst-clustering computation in lib/clustering.mjs excludes has_catalyst: false rows by construction, so ARCT-810’s attribution status computes CLEAN. Had that one flag been true, the same computation returns INDETERMINATE with a zero-day gap against ARCT-810 — the two half-year windows touch. The computed CLEAN is what the program document records, because transcribing the computation rather than second-guessing it is what 03b-program-spec.md requires; but a reader should know that a Phase 3 go/no-go on the company’s other lead rare-disease asset is guided into the quarter immediately after ARCT-810’s readout, and that the clean attribution rests on a third-party boolean rather than on the two events being genuinely far apart.

C.3 Financial position

The recomputed runway and the company’s own statement agree closely, and neither yet includes the $12 million CSL termination payment or the release from roughly $16 million of R&D credit liabilities announced on 2026-08-06. Both of those improve the picture after the June 30 balance sheet date. A financing before the Q3 2026 ARCT-810 readout is unlikely on this evidence: the company has more than two years of cash, has just been handed a one-off payment, and has not sold stock in three years.

Dilution history. Every registered offering in the last 24 months, plus shelf capacity.

The filing record and the share count agree, which is what makes this finding solid rather than an absence of evidence. Shares outstanding went 27,120,603 (2025-05-06) → 27,154,529 (2025-08-08) → 28,412,537 (2025-11-05) → 28,423,069 (2026-02-27), and have been flat at 28,423,069 through 2026-08-04 [VERIFIED — EDGAR XBRL companyconcept dei:EntityCommonStockSharesOutstanding]. The one real increase, about 1.26 million shares (+4.6%) between the August and November 2025 10-Q cover dates, has no 424B5 behind it in the filing feed; option exercises and share vesting are the ordinary explanation, but this sweep did not confirm the mechanism and does not assert one.

One plain line on the likelihood of a raise before the next catalyst: low. Runway extends more than two years past the Q3 2026 readout, no stock has been sold since 2023, and the fresh shelf is undrawn.

C.4 Valuation frame

Both the 52-week range and the position within it are derived in node from the committed price cache, never by loading that cache into the analysis, per 03a-company-spec.md C.4.

What this frame says in one sentence. With $191.5 million of cash against a $225.7 million market capitalisation, roughly 85% of the company’s market value is its cash, and the entire pipeline — two clinical rare-disease programmes, an approved vaccine and four regained vaccine programmes — is carried at about $34 million. Cash alone is $6.74 per share against a $7.94 share price. The stock also sits 13.2% up a 52-week range whose high is more than three times spot, and it printed that 52-week low of $5.50 only three weeks ago, on 2026-07-24.

C.5 Ownership and flow

Short interest is the single most striking ownership fact here, and its units are confirmed. BPIQ reports short_float as 0.27685. Dividing FINRA’s authoritative 7,206,773 short shares by an estimated non-affiliate float of 26,153,000 (shares outstanding less the 7.99% insider holding) gives 27.56% — agreeing with BPIQ to within two hundredths of a percentage point. So on this ticker BPIQ’s short_float reads as a percentage of float, and the two sources agree. That is worth recording because it is the opposite of the CNTB case in 02-connectors.md, where the same field was 3.4× the FINRA figure under every reading. One in four shares outstanding is sold short, and at 16.52 days to cover the position cannot be closed quickly.

Insider flow: no conviction buying, and none for nearly four years. Every insider transaction in the last 24 months is a grant at a stated price of $0.00 — seven directors each received 15,000 options on 2026-06-05 (struck at $7.30), the CFO 100,000 on 2026-05-01, and the CEO 175,000 on 2025-12-17 [VERIFIED — BPIQ fetch_company_insider_transactions 2026-08-13]. The last open-market purchase by any insider was 5,000 shares by CEO Joseph Payne at $16.51 on 2022-11-23. Set against that, the disposals were large and were made far above spot: Chief Scientific Officer Pad Chivukula sold repeatedly between 2020 and 2024 at prices from $16.07 to $96.19, and Ultragenyx — once a 10% owner — exited entirely across 2020 and 2021 at $45.83 to $105.54. Read plainly: insiders sold heavily into strength years ago and have bought nothing on the way down to $7.94.

The insider connector agreed with the filings on this ticker. 02-connectors.md records fetch_company_insider_transactions returning zero rows while Form 4s exist, on both TLSA and CNTB. It did not fire here: the connector’s seven director grants dated 2026-06-05 match seven Form 4 filings dated 2026-06-15 in the EDGAR feed, and the CFO’s 2026-05-01 grant matches a Form 4 filed 2026-05-07. The gap is a connector property that appears on some tickers and not others, and this is a clean one.

Concentration. Institutional ownership near 79% with only one hedge-fund holder (hf_holding_count: 1) suggests the register is held by index and passive funds rather than by event-driven money positioned for the readout. Vanguard disaggregated its holdings and reported zero shares on 2026-03-26, and Balyasny reported no stake on 2026-02-15 — two exits inside six months. Nobody is obviously positioned for this catalyst; a great many shares are positioned against it.

C.6 Options chain and its readability

Plain-English takeaway first: the options chain on this stock cannot price the ARCT-810 event, and no single number should be quoted from it. The expiry that would cover a Q3 2026 readout is 2026-09-18. At the strike nearest the money, buying both a call and a put costs somewhere between 12% and 31% of the share price depending on whether you transact at the bid or the ask — a spread so wide that the “implied move” is a bracket, not an estimate. Fewer than 220 contracts are open at that strike in total, and six contracts traded there on the day of the sweep.

The nearer 2026-08-21 expiry is worse, and carries the artifacts 02-connectors.md warns about directly: three of its six call strikes report implied volatility of exactly 0.01488 — the known floor artifact — and the $2.50 call reports 6.20985 with a delta of 0.948, a deep-in-the-money contract whose volatility number is meaningless. Both are treated as null here.

Consequence for the program document: the “expected move around this event” line in the ARCT-810 README must give a bracket and say the chain is unusable, not quote an options-implied number.

C.7 Reaction to past catalysts

Intraday moves as fetch_company_historical_catalysts reports them, each cross-checked against the press feed for the same date and against the committed price cache. Two rows are overturned by that cross-check.

The single most useful row is not in this table, because BPIQ does not carry it. On 2025-06-30 Arcturus announced positive interim Phase 2 multiple-dose data for ARCT-810 itself — the closest possible analogue to the upcoming event. The price cache shows what happened: the stock closed $13.33 on 2025-06-27 and $13.01 on 2025-06-30, a −2.4% move on the day the good news landed [VERIFIED — data/prices/ARCT.json via lib/prices.mjs]. The move that did happen came a week earlier, on the announcement that a KOL presentation of that data would be held: the stock ran from $12.51 on 2025-06-23 to $14.41 on 2025-06-26, +15.2% in four sessions, and then gave it all back into the data itself. Any expectation about the Q3 2026 readout has to be set against that.

Two lessons for the program document. First, this company’s positive non-data catalysts (designations, IND clearances, enrollment milestones) reliably produce +6% to +17% single-day moves, while its actual clinical data has produced one −50% session and one −2.4% session. Second, BPIQ’s intra_day_price_change_percent is open-to-close and systematically hides overnight gaps, which on this ticker is the difference between a +17% record and a −50% one — so every historical figure used downstream is taken close-to-close from the price cache, not from the connector.

C.8 Company data-quality flags

1. market_cap is computed off the previous close — the known bug fires on this ticker. BPIQ reports $216,015,312. Divided by the EDGAR-filed 28,423,069 shares that is exactly $7.6000, the reported previous_close, against a $7.94 last price. This is the MNOV failure mode in 02-connectors.md, not the CNTB stale-share-count one: the share count is current (2026-08-04, filed 2026-08-06) and the price is stale. C.4 recomputes from the filed count and the price actually wanted.
2. max_52_week_position fires the same way. BPIQ reports 0.11248. Computed off the previous close, (7.60 − 5.50) ÷ (24.17 − 5.50) = 0.11248 exactly; computed off the last price it is 0.1323. C.4 derives the figure from the price cache and does not read this field.
3. enterprise_value does not reconcile against BPIQ’s own cash field. BPIQ reports $31,832,636. Its own market cap less its own cash is $24,532,312, leaving an unexplained residual of $7,300,324. The Q2 2026 press release does not disclose debt separately, so this sweep cannot say whether the residual is debt, a lease liability or an error. It is reported as an open item rather than smoothed over, and C.4’s enterprise value is recomputed from the filed share count, the last price and balance-sheet cash instead.
4. A press-feed headline is mis-dated by five months, and would have corrupted C.7. An MSN item in the feed dated 2026-03-23 reads “Arcturus Therapeutics stock plunges 50% after weak cystic fibrosis trial data”. The price cache shows 2026-03-23 closed at $6.87 against $6.63 on 2026-03-20 — up 3.6%. The 50% plunge it describes is the 2025-10-22 session, five months earlier. Taking the aggregator date at face value would have invented a second CF-data collapse that never happened and put it inside this year’s trading history.
5. has_catalyst on the ARCT-032 row shapes the clustering result. Recorded in full at the end of C.2 rather than repeated here.
6. An EDGAR submissions read returned another issuer’s data mid-sweep, and was caught. A first read of data.sec.gov/submissions/CIK0001768224.json was later found to contain 321 filings with a 10-K dated 2026-03-18 and a 10-Q dated 2026-05-15 — neither of which matches Arcturus, whose 10-K was filed 2026-03-03 and 10-Q 2026-08-06. Re-fetching and verifying the cik, name and tickers fields inside the payload returned the correct 410-filing feed for Arcturus. The discrepancy was noticed because the wrong file implied 424B5 offerings in November 2025 and January 2026 that the flat share count contradicted. Every EDGAR figure in this document comes from the verified re-fetch, and the dilution finding in C.3 rests on the share-count series agreeing with the filing record independently. Recorded because a payload that parses cleanly and describes the wrong company is the most dangerous kind of connector fault: nothing announces it.
7. FINRA’s publication lag was shorter than 02-connectors.md records. That file notes that on 2026-08-10 the 2026-07-15 settlement was newest and 2026-07-31 was not yet published. On 2026-08-13 the 2026-07-31 settlement returned data. Not a bug — the lag simply resolved — but worth recording so a later sweep does not assume the older observation still holds.