13F Insight
DOSSIER · 13F-HR · Q1 2026

East Coast Asset Management, LLC.

$303M in tracked AUM across 68 positions as of Q1 2026.

EC
CIK 0001579254 · last filed Mar 31, 2026
Total AUM
$303M
as of Q1 2026
Holdings
68
—
positions
Whale Score
56
56
tracked
Activity
—
no data
changes this Q
AI Analysis · Q1 2026
Comprehensive Analysis of SEC 13F Filing: East Coast Asset Management, LLC
1. Portfolio Overview

East Coast Asset Management has undergone a significant transformation in the quarter ending September 30, 2025. The firm executed a substantial reduction in portfolio size, with total assets under management (AUM) decreasing by 40.9%, dropping from $301.41M to $178.02M. This reduction was driven more by active position liquidation than by market depreciation, evidenced by the sale...

The portfolio has shifted toward a high-conviction, concentrated strategy. The number of holdings was streamlined from a previously larger set to just 19 securities. The top four positions—GOOG, PRM, META, and TSLA—now command a dominant 81.55% of the total portfolio value. This indicates a pivot away from broad diversification toward a focused "barbell" strategy heavily weighted in large-cap technology/communication services and a specific healthcare holding (Perimeter Solutions).

2. Key Holdings
Analysis generated by 13F Insight from SEC Form 13F filing data · Q1 2026. Methodology

Quarter at a glance — Q1 2026

Position-change comparison pending.

No quarter-over-quarter changes available.

Top 10 holdings

By portfolio weight as of Q1 2026.

#HoldingValueSharesWeight
01
GOOG
ALPHABET INC
$48M166K15.7%02
TSLA
TESLA INC
$37M100K12.2%03
PRM
PERIMETER SOLUTIONS INC
$33M1.4M10.9%04
TDG
TRANSDIGM GROUP INC
$27M23K8.9%05
SATS
ECHOSTAR CORP
$16M137K5.3%06
BRK/B
BERKSHIRE HATHAWAY INC DEL
$14M30K4.8%07
AMZN
AMAZON COM INC
$12M59K4.1%08
MA
MASTERCARD INCORPORATED
$11M23K3.8%09
WWD
WOODWARD INC
$10M29K3.4%10
AAPL
APPLE INC
$10M39K3.2%

Filing history

2026Q1Mar 31
$303M▼ 10.8%
68 positionsView →2025Q4Dec 31
$340M▲ 91.0%
69 positionsView →2025Q3Sep 30
$178M▼ 40.9%
19 positionsView →2025Q2Jun 30
$301M▲ 6.7%
69 positionsLocked2025Q1Mar 31
$282M▼ 5.7%
69 positionsLocked2024Q4Dec 31
$299M▼ 0.6%
71 positionsLocked2024Q3Sep 30
$301M▲ 9.5%
73 positionsLocked2024Q2Jun 30
$275M▲ 0.3%
70 positionsLocked2024Q1Mar 31
$274M▲ 12.0%
69 positionsLocked2023Q4Dec 31
$245M▲ 10.8%
64 positionsLocked2023Q3Sep 30
$221M▼ 1.0%
62 positionsLocked2023Q2Jun 30
$223M▼ 1.5%
63 positionsLocked
Showing 12 of 53