Portolan Capital Management, LLC

Q1 2026 13F-HR Holdings

Location
Boston, MA
Holdings as of
3/31/2026
Date filed
5/15/2026
Form type
13F-HR
Num holdings
144
Total value ($000)
$1,878,963
Net value change ($000)
+12,539 (0.7%)
New positions
30
Sold out positions
41
Turnover %
31.5%
Sector allocation + QoQ delta (equities-only)
Prev filing: 2/17/2026 Next filing: — SEC filing

Snapshot: Change Analysis

Compared to Q4 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)
PARR 43,462 NEW
VIRT 40,761 325.1%
PBF 38,096 NEW
CRGY 34,780 10382.1%
MUSA 23,763 NEW
FN 23,607 476.6%
ECO 21,785 397.8%
CRCL 20,398 NEW
DHT 19,947 NEW
UTHR 19,708 110.1%
Top Reduces (Value $000, Stocks/ETFs)
CSTL -34,127 -50.7%
FSLR -20,575 -100.0%
FOUR -20,103 -68.2%
GENI -20,014 -61.8%
FAF -19,702 -100.0%
ZETA -19,097 -71.2%
QTRX -18,414 -64.0%
DOMO -17,595 -96.7%
SPHR -16,700 -100.0%
WRBY -16,299 -60.7%
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