HOWL Werewolf Therapeutics, Inc.

BEARISH Impact: 6/10 144
Horizon days Filed May 28, 2026 Processed 12d 9h ago SEC 0001628280-26-038889
Latest settled — T+5d
HOWL ▼ -12.89% at T+5d
SHORT call ✓ call won +12.89% · α vs SPY +10.37% · entry $0.4500 → $0.3920
Next anchor: T+20d in 16d
Last close $0.3820 (close Jun 8) · +15.11% from $0.4500 entry (call sign-flipped)
Entry anchored
May 28, 2026
via day open
T+1d
+3.56%
call -3.56% · α -3.30%
$0.4660
settled 12d ago
T+5d
-12.89%
call +12.89% · α +10.37%
$0.3920
settled 6d ago
T+20d
call — · α —
in 16d
T+60d
call — · α —
in 2mo

Price Chart

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Executive Summary

A cluster of 8 Form 144 filings by MPM-affiliated entities (MPM Oncology Innovations Fund, MPM Asset Management, UBS Oncology Impact Fund, and multiple MPM BioVentures funds) were filed on 2026-05-28, signaling intent to sell shares of Werewolf Therapeutics (HOWL). The filings are aggregate across the MPM platform and represent a coordinated insider distribution. At a ~$24M market cap, the selling entities appear to be major early investors. This batch follows 10 insider sells totaling $346K in the past 30 days, reinforcing a pattern of liquidation by large holders.

Actionable Insight

A coordinated Form 144 cluster by MPM entities at a ~$24M market cap is a strong bearish signal for HOWL. These are likely early-stage investors seeking to exit, creating overhang. Monitor for actual sales in coming days; if the selling pressure materializes, HOWL could face significant downside given the low liquidity of a $24M micro-cap. Consider short positions or avoiding HOWL until the distribution clears.

Key Facts

  • 8 Form 144 filings filed on 2026-05-28 by MPM-affiliated funds and UBS Oncology Impact Fund
  • Selling entities include MPM Oncology Innovations Fund LP, MPM Asset Management Investors BV2014 LLC, MPM ASSET MANAGEMENT LLC, UBS Oncology Impact Fund LP, MPM BioVentures 2014 (B) LP, MPM BioVentures 2014 LP
  • All filings specify intent to sell shares of Werewolf Therapeutics (HOWL) common stock
  • Prior 30 days show 10 insider sales totaling ~$346K
  • Market cap is approximately $24M — a small-cap, early-stage biotech
  • No specific share amounts or dollar values are available in the document text
  • This is a coordinated distribution by major early investors, not a single insider

Financial Impact

Material — multiple large holders signaling exit at a $24M market cap, representing a significant portion of the float

dilutionliquiditysupply

Risk Factors

  • Form 144 indicates intent, not guaranteed sale — sales may not occur
  • If MPM entities sell a large block, the stock could gap down significantly
  • Low market cap ($24M) amplifies impact of any insider selling on price
  • Biotech sector risk — negative clinical data could compound selling pressure

Market Snapshot

Exchange
Nasdaq
Sector
Pharmaceutical Preparations
Analyst Consensus
80% bullish (10 analysts)

Documents Analyzed

This report is based on 8 SEC documents filed with EDGAR.

DocumentAccession Number
144 Filing (HOWL) — Batch item 10001628280-26-038889
Document: 0001628280-26-038889-index.html0001628280-26-038891
Document: 0001628280-26-038889.txt0001628280-26-038892
144 Filing (HOWL) — Batch item 40001628280-26-038891
144 Filing (HOWL) — Batch item 50001628280-26-038892
144 Filing (HOWL) — Batch item 60001628280-26-038893
144 Filing (HOWL) — Batch item 70001628280-26-038895
144 Filing (HOWL) — Batch item 80001628280-26-038896
11 reports for HOWL
Performance horizon
80% Hit rate 4 of 5 directional calls best @ T+20▲ +37.43%Apr 27, 2026
Filters
Rows
Reports for HOWL — sortable, filterable
Type Now
May 28, 2026
12d ago
144
BEARISH ★ 6/10
$0.4500 $0.3920▲ +12.89%▲ +10.37%$0.3820 (+15.11%)
May 20, 2026
20d ago
Insider Cluster
NEUTRAL ★ 4/10
$0.4220 $0.4500▲ +6.64%▲ +4.79%$0.3820 (−9.48%)
May 18, 2026
22d ago
144
BEARISH ★ 6/10
$0.4280 $0.4900▼ −14.49%▼ −12.19%$0.3820 (+10.75%)
May 11, 2026
29d ago
144
BEARISH ★ 6/10
$0.6320 $0.4950▲ +21.68%▲ +21.75%$0.3820 (+39.56%)
May 7, 2026
4w ago
Insider Cluster
BEARISH ★ 6/10
$0.6200 $0.5840▲ +5.81%▲ +7.31%$0.3820 (+38.39%)
May 1, 2026
5w ago
144
NEUTRAL ★ 2/10
$0.6900 $0.6610▼ −4.20%▼ −7.14%$0.3820 (−44.64%)
May 1, 2026
5w ago
144
NEUTRAL ★ 4/10
$0.6900 $0.6610▼ −4.20%▼ −7.14%$0.3820 (−44.64%)
May 1, 2026
5w ago
144
BEARISH ★ 5/10
$0.6900 $0.6610▲ +4.20%▲ +7.14%$0.3820 (+44.64%)
Apr 29, 2026
5w ago
144
NEUTRAL ★ 2/10
$0.7200 $0.6200▼ −13.89%▼ −15.62%$0.3820 (−46.94%)
Apr 29, 2026
5w ago
144
NEUTRAL ★ 2/10
$0.7200 $0.6200▼ −13.89%▼ −15.62%$0.3820 (−46.94%)
Showing 10 of 11

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