Portolan Capital Management, LLC

Q4 2025 13F-HR Holdings

Location
Boston, MA
Holdings as of
12/31/2025
Date filed
2/17/2026
Form type
13F-HR
Num holdings
155
Total value ($000)
$1,866,424
Net value change ($000)
+18,400 (1.0%)
New positions
57
Sold out positions
21
Turnover %
30.3%
Sector allocation + QoQ delta (equities-only)
Prev filing: 11/13/2025 Next filing: — SEC filing

Snapshot: Change Analysis

Compared to Q3 2025
Methodology: sector metrics are equities-only; instrument mix chart is ex-options; options exposure is shown separately. Why this matters.
Top Adds (Value $000, Stocks/ETFs)
AKAM 45,747 NEW
BIDU 33,849 5604.1%
CSTL 32,777 95.0%
FAF 19,702 NEW
LNTH 16,420 107.7%
JBL 16,113 NEW
MRX 16,063 NEW
REAX 15,231 63.2%
BIIB 14,957 NEW
FOUR 14,864 101.7%
Top Reduces (Value $000, Stocks/ETFs)
DBRG -51,323 -80.2%
ELF -49,963 -77.4%
KTOS -32,148 -59.0%
AVAV -28,208 -60.6%
DOMO -24,328 -57.2%
WWW -21,859 -100.0%
CLBT -21,626 -48.2%
POWL -19,966 -44.2%
PSIX -19,232 -100.0%
GDOT -16,483 -76.0%
Instrument mix + QoQ Δ (ex-options)
How this table is calculated: SEC VALUE ($000) is used as reported. For derivatives (PUT/CALL/WARRANT/RIGHT), SEC value represents reported underlying exposure, not premium cash paid/received. Column % is bucket-based: non-options share is calculated inside non-option total, options share is calculated inside options total. Details.
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Instrument:
Issuer Name Ticker Sector Industry Class History Value ($000) % Shares Shares Δ Shares Δ% Value Δ ($000) Value Δ% Principal Option Type