Neuren (NEU): Record Q2 Daybue Sales, Shorts Still Wrong
Acadia posted record Q2 2026 Daybue sales of US$125m, up 30% YoY, and raised guidance again. Six months after we covered Culper's dismantled short thesis, short interest hit a fresh all-time high before pulling back to 5.41%.
In January we covered how Culper Research's February 2024 short thesis on Neuren Pharmaceuticals (NEU) had been dismantled by Daybue's sales performance. Culper predicted peak Daybue revenue would be "a mere fraction" of $800M analyst estimates, forecasting just $316M for 2024. Acadia was already guiding above that at the time, and had just told the market it was targeting $700M in Daybue sales by 2028.
On 5 August 2026, Neuren released the Q2 2026 update from partner Acadia Pharmaceuticals: a record quarter, another guidance upgrade, and the 2028 target reaffirmed.
The Q2 2026 Numbers
Q2 2026 Daybue net sales came in at US$125 million - the highest quarterly figure since launch, up 30% year-on-year and 24% quarter-on-quarter. Acadia said the growth was "almost entirely volume-driven," i.e. more patients on therapy rather than pricing.
| Metric | Q2 2026 | vs Q2 2025 | vs Q1 2026 |
|---|---|---|---|
| Daybue Net Sales | US$125m | +30% | +24% |
| Neuren Royalty Income | US$12.9m | +34% | +24% |
Guidance upgraded again
Acadia raised full-year 2026 Daybue net sales guidance to US$480-510 million, from US$460-490 million previously. That flows through to Neuren's royalty guidance, upgraded to US$53-56 million for FY2026 (from US$50-54 million).
| Metric | Value |
|---|---|
| FY2026 Daybue Net Sales Guidance | US$480-510m |
| FY2026 Neuren Royalty Guidance | US$53-56m |
| 2028 Daybue Target (reaffirmed) | US$700m |
The multi-year trend:
| Period | Daybue Net Sales (US$m) |
|---|---|
| CY2023 (Apr-Dec) | 177 |
| CY2024 | 348 |
| CY2025 | 391 |
| CY2026E (Acadia guidance) | 480-510 |
Sales have roughly tripled in under three years, on a drug Culper called a "total flop" in February 2024.
STIX adoption is ahead of plan
DAYBUE STIX, the powder formulation of trofinetide, became broadly available in the US from early April 2026. By the end of Q2:
- 40% of all US Daybue patients were on STIX
- Around 45% of STIX demand came from new or returning patients, not just existing patients switching formulation
- Neuren CEO Jon Pilcher described uptake as "exceeding expectations"
That's relevant to one of Culper's original claims - that patient retention issues would cap Daybue's addressable market. Acadia had already refuted that with its 76% six-month retention figure back in 2024; STIX now pulling in new patients faster than expected is a further data point against it.
Europe moves from "if" to "when"
The CHMP adopted a positive opinion at the end of June 2026, following a re-examination procedure, recommending EU marketing authorisation for Daybue in Rett syndrome patients aged five and older. If the European Commission confirms it, the authorisation covers all 27 EU member states plus Iceland, Liechtenstein and Norway. Commercial launch in Germany is anticipated in early Q4 2026.
Under the licence agreement, Neuren is entitled to:
| European Milestone | Value |
|---|---|
| Payment on first commercial sale | US$35m |
| Sales milestone payments (escalating thresholds) | Up to US$170m |
| Tiered royalties | Mid-teens to low-20s % of net sales |
This is the catalyst we flagged as pending back in January - an EMA decision was then expected in Q1 2026. It took a re-examination procedure to get there, but the outcome was positive, and a German launch is now a matter of months away.
Japan remains on track separately: topline trial results are expected September-November 2026, with a regulatory submission anticipated in 2027.
Short interest: a new all-time high, then a pullback
Our January article cited May 2025 as the all-time peak for NEU short interest, at 6.42%. That's since been surpassed - short interest climbed through the first half of 2026 and hit 6.51% on 5 June 2026, a new high, before easing off:
| Period | Short Interest |
|---|---|
| January 2024 (pre-Culper) | 0.30% |
| February 2024 (post-Culper) | 0.93% |
| May 2025 (prior peak) | 6.42% |
| January 2026 | 5.76% |
| 5 June 2026 (new all-time high) | 6.51% |
| 17 July 2026 (low) | 4.88% |
| 31 July 2026 (latest) | 5.41% |
Current position
| Metric | Value |
|---|---|
| Short Interest | 5.41% |
| Short Shares | 6.86 million |
| Short Liability | ~$148.5 million AUD |
| Report Date | 31 July 2026 |
So short interest has come off its June high, but it hasn't gone away, and it was climbing again in the two weeks before this result - up from 4.88% on 17 July to 5.41% by 31 July. Some traders were adding to shorts right before Acadia delivered a record quarter and raised guidance for the second time this year.
Price performance since January
| Metric | January 2026 | August 2026 |
|---|---|---|
| Price | $19.30 | $21.64 |
| 52-Week High | $22.99 | $22.99 |
| 52-Week Low | $8.61 | $11.00 |
| Market Cap | $2.44bn | $2.74bn |
The 52-week low has moved up from $8.61 to $11.00 - the whole trading range has shifted higher. NEU's beta sits at 1.59, so it still moves more than the broader market on news in either direction.
Where the bear case stands now
| Culper's 2024 claim | Current position (Aug 2026) |
|---|---|
| Peak sales "a mere fraction" of $800M | 2028 target reaffirmed at $700M; FY26 alone guided to $480-510M |
| 2024 revenue of $316M | CY2024 actual: $348M. CY2025: $391M. CY2026E: $480-510M |
| Poor patient retention, "total flop" | STIX adoption ahead of plan; 45% of demand from new/returning patients |
Every result since the original report has added to the case against it rather than for it. What's left of the bear case for NEU now looks like ordinary single-asset risk rather than a challenge to the drug itself:
- European Commission decision - CHMP's opinion isn't binding until the EC confirms it; there's timing risk between now and the anticipated Q4 2026 German launch.
- Single-drug concentration - Neuren's royalty income is still almost entirely dependent on Daybue.
- Partner dependency - commercialisation execution sits with Acadia, not Neuren.
- Japan readout (Sep-Nov 2026) - a trial miss here would be the first negative data point since the original short report.
Conclusion
Six months on from calling the Culper thesis dismantled, the data has kept moving the same direction: a record quarter, guidance raised again, a positive CHMP opinion, and STIX uptake ahead of plan. Short interest touched a fresh all-time high of 6.51% in June before easing to 5.41% - but at close to $150 million in liability, there's still real money positioned against a company that has beaten or raised guidance in every update since the short report landed in February 2024.
Disclaimer: This blog post is for informational and educational purposes only and is not financial advice. The information provided is based on data available as of 2026-08-06. Neuren Pharmaceuticals is a biotech stock with inherent risks including regulatory uncertainty and single-product concentration. Short selling data reflects positions as of the report date and changes daily. You should conduct your own thorough research and consult with a qualified financial professional before making any investment decisions. ASXShort.app does not guarantee the accuracy or completeness of the data presented, nor does it guarantee future stock performance.
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