DOSSIER · 13F-HR · Q3 2026

Penbrook Management LLC

$169M in tracked AUM across 102 positions as of Q3 2026.

PM
CIK 0001381055 · last filed Sep 30, 2026
Total AUM
$169M
as of Q3 2026
Holdings
102
—
positions
Whale Score
58
58
tracked
Activity
—
no data
changes this Q
AI Analysis · Q3 2026

Penbrook Management LLC runs a $132M 13F whose defining structural feature is concentration — the top five positions claim roughly one-third of the book, and the most unusual position is not a name but a configuration: Alphabet Class A (GOOGL) and Alphabet Class C (GOOG) held simultaneously across both filings at nearly identical weights (5.0% and 4.9% of portfolio, respectively), folding two share-class lines into a single de-facto Google commitment of almost 10% of total assets — a doubling-down that most peers would resolve by choosing one side. Novo Nordisk ADR (NVO) sits as the largest single-name position at $11.6M (8.8%), though it is worth noting that during Q1 its value declined $4.5M on essentially flat share count, reflecting a 28% pullback in the stock rather than an active reduction by the manager. Amazon (AMZN, 8.2%) and Microsoft (MSFT, 6.2%) provide the U.S. large-cap tech anchor; Moody's (MCO, 4.5%) supplies the financial/analytics-services tilt alongside Blackstone (BX). What makes the Q1 composition read differently from prior periods is the shift at the margin: Planet Labs (PL) was cut by roughly two-thirds during the quarter, a bet that the satellite-imagery thesis is re-pricing; Synchrony Financial (SYF), Fidelity National Financial (FNF), First BanCorp (FBP), and PAR Technology were cleared out entirely; six new names entered — Prothera (clinical-stage biotech), Magnite (programmatic ad-tech), Cryoport (biopharma cold-chain logistics), Extreme Networks (EXTR, enterprise networking), Shell, and Cenovus (energy). The net effect: the book's top-seven conviction layer is unchanged in identity but slightly reduced in absolute value ($144.9M AUM at year-end 2025 fell to $132.1M), suggesting modest redemptions alongside the rotation rather than a clean manager-led restructuring.

When a 13F shows the top-five names commanding 35% of assets, the first question a reader should ask is what risk that creates. For Penbrook, the answer is straightforward: the two positions that most warrant attention both carry the same Alphabet exposure — one deliberate (the dual share-class structure) and one statistical (NVO's price decline repricing roughly 10% of the book without the manager's consent). The NVO situation is worth separating from an active sell: share count remained essentially flat at just under 316,000, and the $4.5M value decline is a passive effect of the GLP-1 stock's 28% pullback over Q1. There is no evidence in the filing that the manager reduced its conviction; the conviction simply got less valuable in dollar terms.

The dual-share Google bet is the more interesting deliberate choice. GOOGL and GOOG both occupy top-five weight, and they track the same underlying business with virtually identical market-cap weighting. The marginal difference in voting rights is meaningful at the shareholder-meeting level but irrelevant to a 13F-value perspective; what the dual-CUSIP position really reflects is either an internal allocation decision (two sub-accounts refilling each Google class independently) or a hedge against the narrow differential in pricing between the two. Either way, the result is a single-company Google bet expressed in a way that makes it harder for a reader to see the aggregate exposure — it requires adding two numbers that are adjacent on the filing but belong to different CUSIPs.

Analysis generated by 13F Insight from SEC Form 13F filing data · Q3 2026. Methodology

Quarter at a glance — Q3 2026

Position-change comparison pending.

No quarter-over-quarter changes available.

Top 10 holdings

By portfolio weight as of Q3 2026. Source: SEC EDGAR 13F-HR filings.

#HoldingValueSharesWeight
01
TRGP
TARGA RES CORP
$18M7K10.6%
02
AMZN
AMAZON COM INC
$13M52K7.6%
03
NVO
NOVO-NORDISK A S ADR
$12M312K7.0%
04
MSFT
MICROSOFT CORP
$11M22K6.6%
05
GOOGL
ALPHABET INC CAP STK CL A
$8M23K4.7%
06
GOOG
ALPHABET INC CAP STK CL C
$8M22K4.5%
07
MCO
MOODYS CORP
$6M14K3.6%
08
CYRX
CRYOPORT INC
$3M201K2.1%
09
M0854Q105
ALLOT LTD SHS
$3M377K1.9%
10
SA
SEABRIDGE GOLD INC
$3M111K1.9%

Filing history

2026Q3Sep 30
$169M▲ 8.1%
102 positionsView →
2026Q2Jun 30
$157M▲ 18.7%
101 positionsView →
2026Q1Mar 31
$132M▼ 8.9%
93 positionsView →
2025Q4Dec 31
$145M▲ 159.4%
97 positionsView →
2025Q3Sep 30
$56M▼ 58.0%
51 positionsLocked
2025Q2Jun 30
$133M▲ 0.5%
102 positionsLocked
2025Q1Mar 31
$132M▼ 9.8%
107 positionsLocked
2024Q4Dec 31
$147M▼ 4.7%
110 positionsLocked
2024Q3Sep 30
$154M▼ 6.1%
106 positionsLocked
2024Q2Jun 30
$164M▲ 1.5%
101 positionsLocked
2024Q1Mar 31
$161M▲ 8.4%
102 positionsLocked
2023Q4Dec 31
$149M▲ 9.1%
103 positionsLocked
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