BlackRock California Municipal Opportunities Fund

BlackRock California Municipal Series Trust

Actively managed U.S. bond fund
$2.44B NAV
282 positions · as of 2026-05-31 · filed 2026-07-24

Fund classification

Classified from what the fund holds · as of 2026 Q2

BlackRock California Municipal Opportunities Fund is an actively managed U.S. bond fund.

Asset class
Bonds
Region
United States
Management
Actively managed
Fund type
Open-end fund
Credit quality
Investment grade
Rate sensitivity
Long duration

Fund profile

As filed in the prospectus · 2025 Q3

The investment objective of BlackRock California Municipal Opportunities Fund (the California Fund or the Fund) is to provide shareholders with income exempt from Federal and California income taxes.

Strategy · summarised

The fund invests at least 80% of its assets in California municipal bonds selected through bottom-up fundamental analysis combined with macroeconomic risk assessment, with particular emphasis on duration management and capital structure positioning. The fund maintains at least 50% in investment-grade securities but may hold up to 50% in non-investment-grade bonds, and may invest up to 20% in non-California municipal securities including taxable municipals and corporate bonds. Because the fund's security selection depends on management's assessment of credit quality, yield, and duration rather than an index, its performance will diverge from any benchmark. The fund may leverage its portfolio through tender option bond transactions and engages in active trading to implement its strategy.

Expenses
0.42% 1.47%across 5 share classes
Share classGrossNet
C0000112990.56%0.56%
C0000113020.49%0.47%
C0000385610.71%0.71%
C0000385621.48%1.47%
C0001997730.42%0.42%

Net is what a holder pays after the adviser's contractual waiver; gross is before it. A waiver can expire.

Portfolio turnover 117.00% · as of 2025 Q3

Allocation

Asset groups · long / short shown separately, never netted · 2026 Q2

99.99%
of net assets
Bonds94.72%
Cash & short-term5.24%
Derivatives0.03%

Look-through blends 1 underlying fund; 0.0% of NAV was not looked through and stays direct-classified.

Latest quarter

What changed since the fund's previous filing

2026Q2 vs 2026Q1: 63 new29 exited

Largest new: United States Treasury, California Housing Finance Agency, iShares California Muni Bond ETF, State of California, Elk Grove Unified School District, San Diego Unified School District, University of California, East Bay Municipal Utility District Water System Revenue

Largest exited: United States Treasury, San Francisco City & County Airport Comm-San Francisco International Airport ×2, San Mateo County Community College District, California Community Choice Financing Authority, Los Gatos Union School District, California Public Finance Authority, California Health Facilities Financing Authority

Return profile

Total return as filed — price change plus distributions reinvested · trailing figures to Apr 2026

1-year
+4.99%
3-year
+11.23%
5-year
+5.54%
Volatility
3.85%
Worst 3-yr fall
-3.77%
Cumulative return· Jun 2023 – Apr 2026

May 2026 has been filed since the trailing figures were struck, so it is not in the table above or the curve — every figure here shares one cut-off, which is what makes them comparable with other funds.

This fund changed legal form during the period shown. The history above is continuous — it spans both eras, and the change is not a gap in reporting.

Debt profile

What this fund holds — value-weighted across its bond and securitized long positions · as of 2026-05-31

Avg coupon
4.77%
Avg maturity
22.35 yr
Coupon type

Share of the fund's debt by how its coupon behaves — the fact that decides whether a rate move reaches this portfolio at all.

17%
floating
Fixed rate77.7%
Floating rate17.1%
Zero-coupon or unclassified5.1%
Maturity ladder

Share of the fund's debt value in each maturity band, shortest first.

<1y10y+
<1y2.1%
1-3y1.0%
3-5y1.3%
5-10y5.0%
10y+90.6%
Flagged holdings
Defaulted: 2.54% · $57.51M · 25 positions
In arrears: none reported
Paid in kind: none reported

These three overlap — one holding can be in arrears and paying in kind at once — so they are shown separately and never summed.

Risk profile

Interest-rate and credit-spread sensitivity, both in years · as of 2026Q2

More of this fund’s sensitivity sits in credit spreads than in interest rates — a rate rally that comes with a credit selloff works against it.

Interest-rate duration
8.21 yr
approx. move per 100bp
Credit-spread duration
8.32 yr
approx. move per 100bp
If rates and spreads both rise 100bp

Where the loss would come from. The two shocks are the same size, so this is the balance of the fund's two sensitivities rather than a bet on one moving more.

≈ -16.5%
of value
Credit spreads50%
Interest rates50%

Filers report the impact of a 0.01% move only, so the total is our own scaling of that one number and overstates the loss on most bonds — read it as approximate, never as precise. The two sensitivities overlap rather than add up: they measure the same positions against different shocks, which is why the durations above are shown side by side and never summed.

Credit risk by quality

Share of the fund's spread duration carried by each credit tier.

+8.32
yrs total
Investment grade+7.22 yr
High yield+1.11 yr
Where the risk sits on the curve

Share of duration at each point, shortest first. A positive figure loses value when spreads widen; a negative one offsets — a credit hedge.

Interest rate8.21 yr total
3 mo30 yr
3 mo0.03 yr0%
1 yr0.16 yr2%
5 yr2.03 yr25%
10 yr2.89 yr35%
30 yr3.10 yr38%
Credit spread8.32 yr total
3 mo30 yr
3 mo0.14 yr2%
1 yr0.14 yr2%
5 yr2.61 yr31%
10 yr4.30 yr52%
30 yr1.13 yr14%

The two bands measure the same positions against different shocks and do not add — a Treasury carries rate duration and no spread duration, a floating-rate credit the reverse. Rate tenors are also summed across every currency the fund discloses.

Show the numbers
TenorRate yrsIG yrsHY yrsIG $/bpHY $/bp
3 mo+0.03+0.01+0.13$2.0k$31.8k
1 yr+0.16+0.13+0.01$32.1k$3.3k
5 yr+2.03+2.56+0.05$626.0k$12.7k
10 yr+2.89+4.01+0.30$979.6k$72.2k
30 yr+3.10+0.51+0.62$124.8k$150.5k

Dollar change per 1bp of spread movement, as filed and sign-anchored. A blank cell was not filed; a zero was.

Holdings

By % of NAV · equity positions carry filed share counts · every resolvable issuer links to its company page

Issuer%NAVValue
United States Treasury4.70%$114.83M
California Community Choice Financing Authority5.00% floating · due 2056-10-012.65%$64.84M
California Community Choice Financing Authority5.00% floating · due 2054-02-012.20%$53.83M
California Housing Finance Agency3.60% floating · due 2056-07-012.04%$49.99M
iShares California Muni Bond ETF2.02%$49.32M
California Community Choice Financing Authority5.00% floating · due 2056-03-011.98%$48.36M
California State Public Works Board5.00% · due 2049-04-011.82%$44.47M
County of Sacramento CA Airport System Revenue5.25% · due 2049-07-011.55%$38.02M
California State University5.25% · due 2050-11-011.42%$34.80M
City of San Francisco CA Public Utilities Commission Water Revenue5.00% · due 2051-11-011.34%$32.66M
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Reported price is the fund's own reported value divided by its own reported shares at 2026-05-31 — not a live quote, and not what the fund paid.

Top 10 positions are 21.72% of net assets, top 25 37.70%, across 110 issuers.

See more of this fund's book

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