April 2026 Monthly Short Selling Report
Activist short sellers posted a 63% success rate across 16 April campaigns, with Mid Caps averaging -17.9% while Large Caps rallied +8.4% against their reports. Fugazi Research takes Short King honors back to back, this time with a 55% collapse of Avis Budget Group in seven trading days.
Activ8 Newsroom • May 5, 2026
April 2026
Activist Short Selling Performance Report
April produced one of the widest dispersion months of the cycle. A single campaign, Fugazi Research's call on Avis Budget Group, drove a 55% decline in seven trading days, the largest single-campaign move of the month by a wide margin. Beneath that headline number, the rest of the field split sharply: Mid Cap targets averaged a 17.9% decline while Large Cap names rallied 8.4% on average against their reports. Two firms hit Sportradar on the same day. Two firms hit Blaize within 48 hours. Citron Research returned to the field with a high-profile call on Applied Optoelectronics that the AI infrastructure tape promptly absorbed. The result is a month where the median tells one story and the tails tell another.
The Month in Short
- Sixteen reports across five exchanges and four countries delivered an average impact of -5.2%, with a 63% success rate. Five reports drove declines of 5% or more, three crossed the 10% threshold, and one cleared 25%.
- Fugazi Research's campaign against Avis Budget Group (CAR) delivered a -55.04% impact in seven trading days, the largest single-campaign move of the month and the second consecutive month Fugazi has anchored the top of the table.
- Sportradar AG (SRAD) drew simultaneous reports from Muddy Waters and Callisto Research on April 22, both registering identical -21.86% impacts through month end. Same target, same day, two firms.
- Mid Caps averaged -17.9% across six reports. Large Caps averaged +8.4% across four reports, with Citron's AAOI miss and Grizzly's Sinch miss leading the failures column.
- Blaize AI (BZAI) drew two activist reports inside 48 hours from Pelican Way Research and White Diamond Research, both alleging counterparty fabrication in the company's $70M NeoTensr contract. Pelican Way's earlier publication captured the move at -7.98%.
Top Performing Shorts
| Ticker | Research Firm | Impact | Result |
|---|---|---|---|
| CAR | Fugazi Research | -55.04% | |
| SRAD | Callisto Research | -21.86% | |
| SRAD | Muddy Waters Research | -21.86% | |
| BZAI | Pelican Way Research | -7.98% | |
| POET | WolfPack Research | -5.07% |
Stocks That Defied the Reports
| Ticker | Research Firm | Impact | Result |
|---|---|---|---|
| AAOI | Citron Research | +17.61% | |
| SINCH | Grizzly Research | +16.84% | |
| WELL | Land & Buildings | +3.87% | |
| AVNW | GlassHouse Research | +2.64% | |
| SHAZ | Bleecker Street Research | +2.11% |
Market Breakdown
By Exchange
Geographic Distribution
Industry Analysis
| Industry | Reports | Key Tickers | Avg Impact |
|---|---|---|---|
| Software (Application) | 2 | SRAD | -21.86% |
| Rental & Leasing Services | 1 | CAR | -55.04% |
| Asset Management | 2 | PGHN, HLNE | -4.25% |
| Aerospace & Defense | 1 | FJET | -3.27% |
| Regulated Electric | 1 | FRMI | -2.66% |
| Capital Markets | 1 | FIGR | -2.50% |
| Semiconductors | 4 | BZAI, POET, AAOI | +1.66% |
| IT Services | 1 | SHAZ | +2.11% |
| Communication Equipment | 1 | AVNW | +2.64% |
| REIT (Healthcare) | 1 | WELL | +3.87% |
| Telecommunications | 1 | SINCH | +16.84% |
Market Cap Analysis
Firm Performance Rankings
Notable Campaigns
The Avis Implosion
-55.04%Fugazi's case against Avis Budget Group centered on $25.3 billion in indebtedness against negative stockholders' equity of $3.1 billion, leverage running at roughly 8x adjusted EBITDA, and a debt-financed buyback program that compressed the float from approximately 60 million shares to 35.26 million while concentrating ownership in SRS Investment Management's hands. The market priced the disclosure within a week.
Sportradar's Twin Strike
-21.86%Two firms published on the same target on the same day, and the price action came back identical. Muddy Waters disclosed a six-month investigation alleging Sportradar facilitates illegal gambling operators, including 47 identified through proprietary source-code fingerprinting. Callisto Research published its own thesis simultaneously. Both campaigns recorded -21.9% impact through month end.
The AAOI Misfire
+17.61%Citron's X post on Applied Optoelectronics framed the company as the "Anti-Lumentum," arguing AAOI trades at 112x forward earnings on commodity 31% margins while its only meaningful customer (Oracle) carries $100 billion in debt and negative free cash flow. The AI infrastructure tape absorbed the report. AAOI rallied an additional 17.6% over the measurement window. The thesis remains intellectually intact; the timing did not.
The Blaize Two-Speed
-7.98%BZAI drew two activist reports within 48 hours. Pelican Way's April 28 report alleged the NeoTensr counterparty in Blaize's $70 million contract was a fabricated entity (registered four days before contract signing, $2 million in capital), generating -8.0% over three trading days. White Diamond's April 30 follow-up extended the thesis to include similar Starshine and counterparty patterns but landed too late in the measurement window to register meaningful impact.
Strategic Insights
Mid Caps Carried The Month
The six Mid Cap reports averaged -17.9% impact, anchored by Avis Budget (-55.0%), Sportradar (-21.9%, twice), and four further declines from Hunterbrook on Hamilton Lane, Fuzzy Panda on Fermi, and Morpheus on Figure Technology. The Large Cap segment ran the opposite direction at +8.4% across four reports. The pattern is consistent with a familiar dynamic: the $2B to $10B band combines enough float liquidity to enable meaningful price discovery with enough single-narrative concentration to react sharply when the narrative is challenged.
AI Infrastructure: Two Theses, Two Outcomes
Six of April's reports targeted AI-adjacent companies (Blaize twice, SharonAI, Fermi, POET, Applied Optoelectronics). Reports anchored on operational fraud or counterparty risk landed: Pelican Way on Blaize at -8.0%, Fuzzy Panda on Fermi at -2.7%, WolfPack on POET at -5.1%. Reports anchored primarily on valuation underperformed, with Citron's AAOI call rallying 17.6% against the thesis. The implication for short selectors: the AI bull case continues to be difficult to short on multiples alone, but pattern-based fraud theses retain their edge.
A Coordinated Strike on Sportradar
April 22 marked the only instance this month of two firms publishing on the same target on the same day. Muddy Waters and Callisto Research both disclosed positions in Sportradar AG, and both campaigns recorded identical -21.9% impact through April 30. Whether the timing reflects genuine convergence on the same thesis or coincidence, the cumulative pressure produced one of the cleanest outcomes of the month. Joint or near-simultaneous publication remains rare; when it does happen, the price action tends to be additive rather than dilutive.
Bull Market Resistance at the Top of the Cap Spectrum
Citron Research on AAOI (+17.6%), Grizzly Research on Sinch (+16.8%), and Land & Buildings on Welltower (+3.9%) all underperformed in April. Each thesis remains plausible on a multi-quarter horizon, but the broader tape ran against them in the measurement window. The pattern speaks to a structural challenge: shorting Large Cap names in a momentum regime requires strict timing discipline and the willingness to be wrong for longer than the data window measures.
Short Selling in a Bull Market
Why valuation-driven shorts get squeezed first in momentum tape, how to measure the rubber band, and what the AI narrative effect looks like in the data.
The PDT Wall Comes Down June 4
A structural change to the retail short-selling audience is six weeks away. On June 4, the amended FINRA Rule 4210 takes effect, retiring the $25,000 pattern day trader account threshold in favor of real-time risk monitoring of open positions. For activist short research, the implication is straightforward: the addressable retail audience expands meaningfully for the first time since the original rule was rushed into place after the dot-com crash. We covered the rule change and what it does and does not change in detail.
The $25,000 Wall Comes Down
FINRA's amended Rule 4210 retires the static account minimum in favor of real-time risk monitoring. What changes for active traders, and what stays the same.
Short King of the Month
Short King of the Month
Fugazi Research
Fugazi's seven trading day campaign against Avis Budget Group delivered April's largest single-campaign decline by a wide margin. The thesis built directly on the company's own disclosures: $25.3B in debt against negative equity, leverage at 8x EBITDA, and a buyback program that handed control to a single investor without an arm's length transaction. Mid Cap, NASDAQ-listed, fully shortable for retail. Back to back with March.
The Bottom Line
April 2026 produced a 63% success rate on 16 reports and an average impact of -5.2%, but the headline numbers obscure a wide dispersion of outcomes underneath. One campaign drove a 55% decline in seven trading days. Three more campaigns crossed the 10% threshold. Four others rallied through their reports, including two of the highest-profile names of the month.
The cap-tier signal was the cleanest takeaway. Mid Caps remained the most fertile ground at -17.9% average impact; Large Caps continued to be the most resistant at +8.4%. Inside the AI complex, fraud-pattern theses landed while valuation-only theses did not. Outside it, two firms hitting the same target on the same day produced one of the cleanest outcomes of the month.
The structural backdrop continues to shift. AI valuations remain stretched, and a small but growing share of fraud-pattern shorts in that space have begun to hit. The June 4 PDT sunset will broaden the addressable retail audience for activist short research. May will reveal which of April's narratives was a one-off and which was the start of a trend.
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