Mitsui Sumitomo Insurance Co Ltd

Fundamental diversified ★Signal financials specialist (100%) CIK 1142206
Long book
$3.90B
Q1 2026
Positions
1
Top-10 weight
100%
concentration
Last quarter
+9.7%
SPY +14.8%
Turnover
0%
of book per quarter

Strategy in plain words

auto-generated from filings

Mitsui Sumitomo Insurance Co Ltd is a diversified fundamental manager, specialised in financials (100% of the long book), running a $3.90B US long book across 1 positions.

The portfolio is extremely concentrated — the top 10 positions are almost the whole book. The book barely moves quarter to quarter — a patient, low-turnover holder. Current anchor positions: WR BERKLEY CORP.

We rate its filings as signal-bearing: position changes reflect genuine views.

Implied long-book return vs S&P 500

methodology: positions priced quarterly, no shorts/options
Fund long book S&P 500
Q4 2025
-5.4%
Q1 2026
+9.7%

Sector allocation

Financials
100%

Long book by quarter

$3.54B
Q4 2025
$3.90B
Q1 2026

What does Mitsui Sumitomo own?

Q1 2026 13F
CompanySectorSharesValue% of bookChange
WRB WR BERKLEY CORPFinancials58.8M$3.90B100.0%+16.3%

13F filing history

PeriodFormFiledEntriesReported valueFlagsSource
Q1 202613F-HRMay 14, 20261$3.90B canonicalSEC ↗
Q4 202513F-HRFeb 17, 20261$3.54B canonicalSEC ↗