Blackrock Bond Fund NPORT-P BlackRock Sustainable Total Return Fund (Dec 2023 report)

Schedule

of

Investments

(unaudited)

December

31,

2023

BlackRock

Sustainable

Total

Return

Fund

2

(Percentages

shown

are

based

on

Net

Assets)

Security

Par

(000)

Pa

r

(

000)

Value

Asset-Backed

Securities

Cayman

Islands

—

6.8%

(a)(b)

AGL

Core

CLO

4

Ltd.,

Series

2020-4A,

Class

A1R,

(3-mo.

CME

Term

SOFR

at

1.07%

Floor

+

1.33%),

6.75%,

04/20/33

.................

USD

250

$

249,877

Anchorage

Capital

CLO

8

Ltd.,

Series

2016-8A,

Class

BR2,

(3-mo.

CME

Term

SOFR

at

1.80%

Floor

+

2.06%),

7.45%,

10/27/34

.......

250

249,203

Bridge

Street

CLO

II

Ltd.,

Series

2021-

1A,

Class

A1A,

(3-mo.

CME

Term

SOFR

at

1.23%

Floor

+

1.49%),

6.91%,

07/20/34

............

250

249,825

CIFC

Funding

Ltd.,

Series

2020-3A,

Class

A1R,

(3-mo.

CME

Term

SOFR

at

1.39%

Floor

+

1.39%),

6.81%,

10/20/34

.................

250

249,685

Gilbert

Park

CLO

Ltd.,

Series

2017-1A,

Class

A,

(3-mo.

CME

Term

SOFR

+

1.45%),

6.85%,

10/15/30

.......

212

212,633

Madison

Park

Funding

XIX

Ltd.

Series

2015-19A,

Class

A1R2,

(3-

mo.

CME

Term

SOFR

at

0.92%

Floor

+

1.18%),

6.59%,

01/22/28

177

176,323

Series

2015-19A,

Class

AR3,

(3-mo.

CME

Term

SOFR

at

1.60%

Floor

+

1.60%),

0.00%,

01/22/37

...

250

250,000

Neuberger

Berman

Loan

Advisers

CLO

35

Ltd.,

Series

2019-35A,

Class

C,

(3-mo.

CME

Term

SOFR

at

2.60%

Floor

+

2.86%),

8.26%,

01/19/33

.

250

252,202

Palmer

Square

CLO

Ltd.,

Series

2021-

3A,

Class

A1,

(3-mo.

CME

Term

SOFR

at

1.41%

Floor

+

1.41%),

6.81%,

01/15/35

............

250

250,189

Pikes

Peak

CLO

8,

Series

2021-8A,

Class

B,

(3-mo.

CME

Term

SOFR

at

1.75%

Floor

+

2.01%),

7.43%,

07/20/34

.................

250

249,653

TCW

CLO

AMR

Ltd.,

Series

2019-1A,

Class

ASNR,

(3-mo.

CME

Term

SOFR

at

1.22%

Floor

+

1.48%),

6.87%,

08/16/34

............

250

248,613

Trimaran

CAVU

Ltd.,

Series

2021-2A,

Class

D1,

(3-mo.

CME

Term

SOFR

at

3.25%

Floor

+

3.51%),

8.89%,

10/25/34

.................

250

245,409

2,883,612

Ireland

—

0.3%

Prodigy

Finance

DAC,

Series

2021-1A,

Class

A,

(1-mo.

CME

Term

SOFR

+

1.36%),

6.72%,

07/25/51

(a)

(b)

....

133

131,366

United

States

—

5.5%

Arbor

Realty

Commercial

Real

Estate

Notes

Ltd.,

Series

2021-FL1,

Class

A,

(1-mo.

CME

Term

SOFR

at

0.97%

Floor

+

1.08%),

6.45%,

12/15/35

(a)

(b)

...............

85

84,045

Diameter

Capital

CLO

1

Ltd.,

Series

2021-1A,

Class

A1A,

(3-mo.

CME

Term

SOFR

at

1.50%

Floor

+

1.50%),

6.90%,

07/15/36

(a)

(b)

....

250

250,053

Security

Par

(000)

Par

(000)

Value

United

States

(continued)

GITSIT

Mortgage

Loan

Trust,

Series

2023-NPL1,

Class

A1,

8.35%,

05/25/53

(a)

(c)

...............

USD

48

$

47,947

Home

Partners

of

America

Trust,

Series

2021-2,

Class

F,

3.80%,

12/17/26

(a)

481

419,940

Legacy

Mortgage

Asset

Trust,

Series

2019-SL2,

Class

M,

4.25%,

02/25/59

(a)

(b)

...............

213

155,507

Lendmark

Funding

Trust,

Series

2022-

1A,

Class

A,

5.12%,

07/20/32

(a)

..

100

99,151

Long

Beach

Mortgage

Loan

Trust,

Series

2006-2,

Class

1A,

(1-mo.

CME

Term

SOFR

at

0.36%

Floor

+

0.47%),

5.83%,

03/25/46

(b)

.....

127

101,005

Mariner

Finance

Issuance

Trust,

Series

2019-AA,

Class

B,

3.51%,

07/20/32

(a)

................

24

24,426

MF1

LLC,

Series

2023-FL12,

Class

A,

(1-mo.

CME

Term

SOFR

at

2.07%

Floor

+

2.07%),

7.42%,

10/19/38

(a)

(b)

100

99,555

Mosaic

Solar

Loans

LLC,

Series

2017-

2A,

Class

C,

2.00%,

06/22/43

(a)

..

19

18,241

Navient

Private

Education

Loan

Trust,

Series

2015-AA,

Class

A3,

(1-mo.

CME

Term

SOFR

at

1.70%

Floor

+

1.81%),

7.18%,

11/15/30

(a)

(b)

....

77

76,972

PRET

LLC,

Series

2021-NPL6,

Class

A1,

2.49%,

07/25/51

(a)

(c)

.......

205

202,028

Progress

Residential

Trust,

Series

2021-SFR10,

Class

F,

4.61%,

12/17/40

(a)

................

496

429,842

Ready

Capital

Mortgage

Financing

LLC,

Series

2023-FL11,

Class

A,

(1-mo.

CME

Term

SOFR

at

2.37%

Floor

+

2.37%),

7.73%,

10/25/39

(a)

(b)

48

48,346

Redwood

Funding

Trust,

Series

2023-1,

Class

A,

7.50%,

07/25/59

(a)

(c)

....

100

98,219

Regional

Management

Issuance

Trust

(a)

Series

2020-1,

Class

A,

2.34%,

10/15/30

...............

74

72,256

Series

2021-1,

Class

A,

1.68%,

03/17/31

...............

100

95,783

2,323,316

Total

Asset-Backed

Securities

—

12.6%

(Cost:

$

5,471,211

)

..............................

5,338,294

Corporate

Bonds

Belgium

—

0.2%

KBC

Group

NV,

(3-mo.

EURIBOR

+

0.72%),

0.38%

,

06/16/27

(b)

(d)

....

EUR

100

102,818

China

—

0.1%

NXP

BV,

5.55%

,

12/01/28

........

USD

32

32,807

France

—

1.5%

(d)

Banque

Federative

du

Credit

Mutuel

SA

0.10%

,

10/08/27

............

EUR

100

98,822

4.13%

,

09/18/30

............

200

231,697

BNP

Paribas

SA

(b)

(3-mo.

EURIBOR

+

0.80%),

0.38%

,

10/14/27

...............

100

101,783

(3-mo.

EURIBOR

+

1.60%),

4.75%

,

11/13/32

...............

100

117,035

Schedule

of

Investments

(unaudited)

(continued)

December

31,

2023

BlackRock

Sustainable

Total

Return

Fund

3

(Percentages

shown

are

based

on

Net

Assets)

Security

Par

(000)

Par

(000)

Value

France

(continued)

Engie

SA,

1.75%

,

03/27/28

.......

EUR

100

$

104,717

654,054

Germany

—

1.2%

Commerzbank

AG,

(3-mo.

EURIBOR

+

1.95%),

5.25%

,

03/25/29

(b)

(d)

....

100

115,897

Deutsche

Bank

AG,

5.37%

,

09/09/27

USD

150

152,110

E.ON

SE,

1.00%

,

10/07/25

(d)

......

EUR

100

106,466

Sartorius

Finance

BV,

4.50%

,

09/14/32

(d)

................

100

114,987

489,460

Italy

—

0.3%

Iren

SpA,

1.95%

,

09/19/25

(d)

......

100

107,835

Spain

—

0.2%

CaixaBank

SA,

(3-mo.

EURIBOR

+

0.85%),

0.38%

,

11/18/26

(b)

(d)

....

100

103,835

Switzerland

—

1.9%

Credit

Suisse

AG

4.75%

,

08/09/24

............

USD

250

248,452

0.45%

,

05/19/25

(d)

...........

EUR

100

105,819

5.00%

,

07/09/27

............

USD

250

250,053

UBS

AG,

0.01%

,

06/29/26

(d)

.......

EUR

200

204,317

808,641

United

Kingdom

—

0.5%

National

Grid

plc,

0.25%

,

09/01/28

(d)

.

100

96,317

RELX

Capital,

Inc.,

4.00%

,

03/18/29

.

USD

14

13,762

SSE

plc,

0.88%

,

09/06/25

(d)

.......

EUR

100

105,994

216,073

United

States

—

25.4%

AbbVie,

Inc.

4.55%

,

03/15/35

............

USD

73

71,588

4.50%

,

05/14/35

............

35

34,231

4.70%

,

05/14/45

............

22

20,935

4.88%

,

11/14/48

............

19

18,522

AEP

Texas,

Inc.

3.95%

,

06/01/28

............

64

61,577

4.70%

,

05/15/32

............

41

40,040

5.25%

,

05/15/52

............

52

50,223

Agilent

Technologies,

Inc.,

3.05%

,

09/22/26

.................

26

24,837

American

Tower

Corp.

5.00%

,

02/15/24

............

12

11,985

3.55%

,

07/15/27

............

78

74,796

3.80%

,

08/15/29

............

196

186,070

2.70%

,

04/15/31

............

44

37,783

American

Transmission

Systems,

Inc.,

2.65%

,

01/15/32

(a)

...........

64

54,146

Amgen,

Inc.

4.05%

,

08/18/29

............

171

167,409

4.40%

,

02/22/62

............

30

25,327

5.75%

,

03/02/63

............

68

71,342

Aon

Corp.,

3.75%

,

05/02/29

.......

25

23,914

AT&T,

Inc.

2.75%

,

06/01/31

............

33

28,930

2.25%

,

02/01/32

............

45

37,212

5.40%

,

02/15/34

............

41

42,284

5.25%

,

03/01/37

............

13

13,052

4.75%

,

05/15/46

............

43

38,866

4.50%

,

03/09/48

............

51

44,488

3.50%

,

09/15/53

............

20

14,514

3.65%

,

09/15/59

............

80

57,336

Security

Par

(000)

Par

(000)

Value

United

States

(continued)

Atmos

Energy

Corp.

2.85%

,

02/15/52

............

USD

10

$

6,772

6.20%

,

11/15/53

............

4

4,689

Autodesk,

Inc.

3.50%

,

06/15/27

............

4

3,883

2.85%

,

01/15/30

............

12

10,816

Baltimore

Gas

&

Electric

Co.,

3.50%

,

08/15/46

.................

74

56,585

Bank

of

America

Corp.

(b)

(1-day

SOFR

+

1.57%),

5.82%

,

09/15/29

...............

217

224,003

(3-mo.

CME

Term

SOFR

+

1.25%),

2.50%

,

02/13/31

..........

38

32,631

(1-day

SOFR

+

1.84%),

5.87%

,

09/15/34

...............

101

105,724

Berry

Global,

Inc.,

1.57%

,

01/15/26

..

251

233,178

Booz

Allen

Hamilton,

Inc.,

5.95%

,

08/04/33

.................

18

19,015

Broadcom,

Inc.

4.30%

,

11/15/32

............

17

16,309

3.42%

,

04/15/33

(a)

...........

61

53,577

3.14%

,

11/15/35

(a)

...........

39

32,018

4.93%

,

05/15/37

(a)

...........

39

37,742

Burlington

Northern

Santa

Fe

LLC

5.40%

,

06/01/41

............

15

15,707

3.30%

,

09/15/51

............

33

25,068

5.20%

,

04/15/54

............

15

15,611

Cameron

LNG

LLC,

3.30%

,

01/15/35

(a)

194

165,185

CenterPoint

Energy

Houston

Electric

LLC

Series

AE,

2.35%

,

04/01/31

....

10

8,563

Series

AF,

3.35%

,

04/01/51

....

15

11,390

Series

AJ,

4.85%

,

10/01/52

....

25

24,339

Charter

Communications

Operating

LLC

5.13%

,

07/01/49

............

8

6,497

4.80%

,

03/01/50

............

108

83,600

3.90%

,

06/01/52

............

46

30,930

4.40%

,

12/01/61

............

15

10,365

3.95%

,

06/30/62

............

21

13,211

Citigroup,

Inc.

(b)

(3-mo.

CME

Term

SOFR

+

1.82%),

3.89%

,

01/10/28

..........

31

29,977

(1-day

SOFR

+

1.89%),

4.66%

,

05/24/28

...............

15

14,880

(3-mo.

CME

Term

SOFR

+

1.41%),

3.52%

,

10/27/28

..........

29

27,427

(1-day

SOFR

+

2.09%),

4.91%

,

05/24/33

...............

87

85,179

(1-day

SOFR

+

2.34%),

6.27%

,

11/17/33

...............

40

42,800

Comcast

Corp.

1.50%

,

02/15/31

............

31

25,406

4.65%

,

02/15/33

............

38

38,229

3.75%

,

04/01/40

............

12

10,322

2.94%

,

11/01/56

............

53

34,859

Commonwealth

Edison

Co.

4.00%

,

03/01/48

............

18

15,247

Series

133,

3.85%

,

03/15/52

....

24

19,397

5.30%

,

02/01/53

............

34

34,523

Crown

Castle,

Inc.,

2.10%

,

04/01/31

.

41

33,393

CSX

Corp.

4.50%

,

11/15/52

............

26

24,128

4.25%

,

11/01/66

............

10

8,516

Schedule

of

Investments

(unaudited)

(continued)

December

31,

2023

BlackRock

Sustainable

Total

Return

Fund

4

(Percentages

shown

are

based

on

Net

Assets)

Security

Par

(000)

Par

(000)

Value

United

States

(continued)

CVS

Health

Corp.

4.78%

,

03/25/38

............

USD

21

$

19,895

5.05%

,

03/25/48

............

27

25,253

6.00%

,

06/01/63

............

5

5,302

Dell

International

LLC

6.02%

,

06/15/26

............

119

121,810

4.90%

,

10/01/26

............

78

78,124

Edison

International

5.75%

,

06/15/27

............

30

30,633

5.25%

,

11/15/28

............

32

32,197

6.95%

,

11/15/29

............

65

70,539

Elevance

Health,

Inc.,

6.10%

,

10/15/52

23

26,073

Equinix,

Inc.

3.20%

,

11/18/29

............

99

90,925

2.15%

,

07/15/30

............

11

9,319

Eversource

Energy,

5.45%

,

03/01/28

31

31,862

Extra

Space

Storage

LP,

5.50%

,

07/01/30

.................

10

10,226

FactSet

Research

Systems,

Inc.,

3.45%

,

03/01/32

............

65

58,209

FirstEnergy

Transmission

LLC,

4.55%

,

04/01/49

(a)

................

36

31,110

General

Motors

Financial

Co.,

Inc.,

5.10%

,

01/17/24

............

199

198,926

Gilead

Sciences,

Inc.

1.65%

,

10/01/30

............

77

64,516

4.60%

,

09/01/35

............

17

16,815

2.60%

,

10/01/40

............

40

29,457

4.80%

,

04/01/44

............

49

47,236

Global

Payments,

Inc.,

5.30%

,

08/15/29

.................

28

28,183

Goldman

Sachs

Group,

Inc.

(The)

(b)

(1-day

SOFR

+

0.91%),

1.95%

,

10/21/27

...............

18

16,467

(1-day

SOFR

+

1.85%),

3.62%

,

03/15/28

...............

138

132,361

(3-mo.

CME

Term

SOFR

+

1.77%),

3.69%

,

06/05/28

..........

30

28,663

(1-day

SOFR

+

1.73%),

4.48%

,

08/23/28

...............

25

24,558

(3-mo.

CME

Term

SOFR

+

1.42%),

3.81%

,

04/23/29

..........

103

97,785

(1-day

SOFR

+

1.77%),

6.48%

,

10/24/29

...............

14

14,855

(1-day

SOFR

+

1.26%),

2.65%

,

10/21/32

...............

108

89,998

(1-day

SOFR

+

1.95%),

6.56%

,

10/24/34

...............

78

85,715

Hartford

Financial

Services

Group,

Inc.

(The),

2.90%

,

09/15/51

........

7

4,667

HCA,

Inc.

5.38%

,

09/01/26

............

61

61,280

3.50%

,

09/01/30

............

189

171,333

5.50%

,

06/15/47

............

12

11,553

Hewlett

Packard

Enterprise

Co.,

5.90%

,

10/01/24

.................

132

132,309

Intel

Corp.

5.70%

,

02/10/53

............

9

9,730

5.90%

,

02/10/63

............

5

5,573

JPMorgan

Chase

&

Co.

(b)

(1-day

SOFR

+

1.33%),

6.07%

,

10/22/27

...............

45

46,292

(1-day

SOFR

+

1.02%),

2.07%

,

06/01/29

...............

33

29,260

Security

Par

(000)

Par

(000)

Value

United

States

(continued)

(3-mo.

CME

Term

SOFR

+

1.52%),

4.20%

,

07/23/29

..........

USD

29

$

28,180

(1-day

SOFR

+

1.57%),

6.09%

,

10/23/29

...............

14

14,720

(1-day

SOFR

+

1.75%),

4.57%

,

06/14/30

...............

27

26,421

(3-mo.

CME

Term

SOFR

+

1.25%),

2.58%

,

04/22/32

..........

10

8,458

(1-day

SOFR

+

1.81%),

6.25%

,

10/23/34

...............

136

147,422

KLA

Corp.

3.30%

,

03/01/50

............

33

25,188

5.25%

,

07/15/62

............

8

8,344

Lowe's

Cos.,

Inc.

2.63%

,

04/01/31

............

37

32,376

5.50%

,

10/15/35

............

8

8,370

2.80%

,

09/15/41

............

71

51,864

Marsh

&

McLennan

Cos.,

Inc.,

5.45%

,

03/15/53

.................

11

11,499

Meta

Platforms,

Inc.,

5.75%

,

05/15/63

27

29,550

MidAmerican

Energy

Co.,

5.85%

,

09/15/54

.................

13

14,382

Moody's

Corp.,

3.25%

,

01/15/28

....

32

30,536

Morgan

Stanley

(b)

(1-day

SOFR

+

0.88%),

1.59%

,

05/04/27

...............

40

36,855

(1-day

SOFR

+

0.86%),

1.51%

,

07/20/27

...............

273

249,360

(1-day

SOFR

+

2.24%),

6.30%

,

10/18/28

...............

21

21,998

(1-day

SOFR

+

1.63%),

5.45%

,

07/20/29

...............

228

232,321

(1-day

SOFR

+

1.83%),

6.41%

,

11/01/29

...............

159

168,506

(1-day

SOFR

+

1.14%),

2.70%

,

01/22/31

...............

66

57,696

(1-day

SOFR

+

3.12%),

3.62%

,

04/01/31

...............

55

50,667

(1-day

SOFR

+

1.88%),

5.42%

,

07/21/34

...............

42

42,625

(1-day

SOFR

+

2.05%),

6.63%

,

11/01/34

...............

85

94,100

Motorola

Solutions,

Inc.

2.75%

,

05/24/31

............

92

78,632

5.60%

,

06/01/32

............

69

71,181

5.50%

,

09/01/44

............

31

30,791

MSCI,

Inc.

(a)

4.00%

,

11/15/29

............

180

169,178

3.63%

,

11/01/31

............

17

14,962

3.25%

,

08/15/33

............

17

14,209

Nasdaq,

Inc.

5.55%

,

02/15/34

............

29

30,127

6.10%

,

06/28/63

............

20

21,591

National

Grid

North

America,

Inc.,

4.67%

,

09/12/33

(d)

...........

EUR

100

117,809

Newmont

Corp.,

2.80%

,

10/01/29

...

USD

60

54,744

NNN

REIT,

Inc.

3.50%

,

04/15/51

............

6

4,334

3.00%

,

04/15/52

............

7

4,562

Norfolk

Southern

Corp.

3.00%

,

03/15/32

............

43

38,233

3.94%

,

11/01/47

............

27

22,522

3.05%

,

05/15/50

............

16

11,380

4.55%

,

06/01/53

............

9

8,218

5.35%

,

08/01/54

............

4

4,157

Schedule

of

Investments

(unaudited)

(continued)

December

31,

2023

BlackRock

Sustainable

Total

Return

Fund

5

(Percentages

shown

are

based

on

Net

Assets)

Security

Par

(000)

Par

(000)

Value

United

States

(continued)

Northern

States

Power

Co.

2.60%

,

06/01/51

............

USD

37

$

24,201

4.50%

,

06/01/52

............

67

61,583

Ohio

Power

Co.

Series

P,

2.60%

,

04/01/30

.....

5

4,379

Series

Q,

1.63%

,

01/15/31

.....

58

47,073

5.00%

,

06/01/33

............

35

35,199

Series

R,

2.90%

,

10/01/51

.....

61

41,309

Omnicom

Group,

Inc.

3.60%

,

04/15/26

............

82

79,912

2.60%

,

08/01/31

............

5

4,297

Oracle

Corp.

3.60%

,

04/01/40

............

120

95,689

4.00%

,

07/15/46

............

51

40,879

4.00%

,

11/15/47

............

4

3,168

3.60%

,

04/01/50

............

8

5,926

5.55%

,

02/06/53

............

9

9,002

Otis

Worldwide

Corp.,

5.25%

,

08/16/28

51

52,416

Owens

Corning,

3.95%

,

08/15/29

...

89

84,762

Pacific

Gas

&

Electric

Co.

4.95%

,

07/01/50

............

45

38,439

3.50%

,

08/01/50

............

110

75,941

PECO

Energy

Co.

3.90%

,

03/01/48

............

34

28,505

2.85%

,

09/15/51

............

29

19,498

4.60%

,

05/15/52

............

26

24,389

4.38%

,

08/15/52

............

10

8,994

Pfizer

Investment

Enterprises

Pte.

Ltd.

4.75%

,

05/19/33

............

72

72,161

5.30%

,

05/19/53

............

97

99,026

Piedmont

Natural

Gas

Co.,

Inc.,

2.50%

,

03/15/31

.................

11

9,392

Public

Service

Co.

of

New

Hampshire,

5.15%

,

01/15/53

............

32

32,390

Public

Service

Electric

&

Gas

Co.

3.70%

,

05/01/28

............

9

8,714

3.60%

,

12/01/47

............

6

4,818

2.05%

,

08/01/50

............

48

27,797

Realty

Income

Corp.,

3.10%

,

12/15/29

5

4,583

Republic

Services,

Inc.

3.95%

,

05/15/28

............

52

50,971

5.00%

,

04/01/34

............

15

15,360

RPM

International,

Inc.,

2.95%

,

01/15/32

.................

25

21,068

Ryder

System,

Inc.

4.30%

,

06/15/27

............

40

39,084

5.65%

,

03/01/28

............

9

9,270

S&P

Global,

Inc.

2.90%

,

03/01/32

............

100

89,258

5.25%

,

09/15/33

(a)

...........

4

4,185

San

Diego

Gas

&

Electric

Co.,

5.35%

,

04/01/53

.................

46

46,538

Southern

California

Edison

Co.

5.65%

,

10/01/28

............

10

10,423

Series

A,

4.20%

,

03/01/29

.....

42

41,165

2.85%

,

08/01/29

............

52

47,387

2.25%

,

06/01/30

............

58

49,774

5.95%

,

11/01/32

............

67

71,980

5.88%

,

12/01/53

............

15

16,126

Sprint

LLC

7.13%

,

06/15/24

............

96

96,416

7.63%

,

02/15/25

............

561

570,810

7.63%

,

03/01/26

............

133

138,948

Tapestry,

Inc.,

7.85%

,

11/27/33

.....

10

10,669

Security

Par

(000)

Par

(000)

Value

United

States

(continued)

Thermo

Fisher

Scientific,

Inc.

4.95%

,

11/21/32

............

USD

52

$

53,661

5.09%

,

08/10/33

............

27

28,142

T-Mobile

USA,

Inc.,

4.75%

,

02/01/28

.

270

269,020

Transcontinental

Gas

Pipe

Line

Co.

LLC

4.60%

,

03/15/48

............

42

37,818

3.95%

,

05/15/50

............

38

30,662

Union

Electric

Co.,

2.63%

,

03/15/51

.

15

9,535

Union

Pacific

Corp.

3.55%

,

05/20/61

............

40

30,041

2.97%

,

09/16/62

............

29

19,505

UnitedHealth

Group,

Inc.

4.25%

,

06/15/48

............

7

6,254

2.90%

,

05/15/50

............

28

19,593

5.88%

,

02/15/53

............

7

7,928

6.05%

,

02/15/63

............

22

25,369

Verizon

Communications,

Inc.

2.55%

,

03/21/31

............

50

43,112

2.36%

,

03/15/32

............

231

192,139

5.05%

,

05/09/33

............

14

14,282

4.40%

,

11/01/34

............

30

28,863

5.25%

,

03/16/37

............

31

32,259

2.65%

,

11/20/40

............

36

25,939

3.70%

,

03/22/61

............

16

12,223

Waste

Management,

Inc.

4.15%

,

04/15/32

............

39

38,076

4.63%

,

02/15/33

............

16

16,050

Wells

Fargo

&

Co.

(b)

(1-day

SOFR

+

1.74%),

5.57%

,

07/25/29

...............

10

10,211

(1-day

SOFR

+

1.79%),

6.30%

,

10/23/29

...............

105

110,662

(1-day

SOFR

+

2.02%),

5.39%

,

04/24/34

...............

51

51,221

(1-day

SOFR

+

1.99%),

5.56%

,

07/25/34

...............

90

91,630

(1-day

SOFR

+

2.06%),

6.49%

,

10/23/34

...............

116

126,195

10,724,439

Total

Corporate

Bonds

—

31.3%

(Cost:

$

13,260,680

)

..............................

13,239,962

Foreign

Agency

Obligations

France

—

0.3%

Electricite

de

France

SA,

3.75%

,

06/05/27

(d)

................

EUR

100

112,547

Italy

—

0.2%

ACEA

SpA,

4.05%

,

09/28/25

(d)

.....

100

103,997

Supranational

—

0.4%

European

Union,

2.50%

,

10/04/52

(d)

.

170

166,574

Total

Foreign

Agency

Obligations

—

0.9%

(Cost:

$

354,717

)

................................

383,118

Foreign

Government

Obligations

Mexico

—

0.8%

United

Mexican

States

8.50%

,

03/01/29

............

MXN

10

57,495

8.50%

,

05/31/29

............

20

115,409

Schedule

of

Investments

(unaudited)

(continued)

December

31,

2023

BlackRock

Sustainable

Total

Return

Fund

6

(Percentages

shown

are

based

on

Net

Assets)

Security

Par

(000)

Par

(000)

Value

Mexico

(continued)

2.66%

,

05/24/31

............

USD

200

$

168,688

341,592

Panama

—

0.4%

Republic

of

Panama,

3.88%

,

03/17/28

200

184,375

Peru

—

0.1%

Republic

of

Peru,

3.55%

,

03/10/51

..

35

26,479

Uruguay

—

0.1%

Oriental

Republic

of

Uruguay,

5.10%

,

06/18/50

.................

25

25,055

Total

Foreign

Government

Obligations

—

1.4%

(Cost:

$

644,265

)

................................

577,501

Municipal

Bonds

California

-

0

.4

%

Bay

Area

Toll

Authority

,

Series

2010S-1

,

RB

,

7.04

%

,

04/01/50

.........

20

25,323

Los

Angeles

Community

College

District

,

Series

2010E

,

GO

,

6.60

%

,

08/01/42

............

5

5,878

Los

Angeles

Unified

School

District

,

Series

2010RY

,

GO

,

6.76

%

,

07/01/34

............

20

22,621

State

of

California

,

Series

2018

,

GO

,

4.60

%

,

04/01/38

............

70

67,296

University

of

California

,

Series

2012AD

,

RB

,

4.86

%

,

05/15/2112

........

15

13,967

135,085

Illinois

-

0

.1

%

State

of

Illinois

,

Series

2003

,

GO

,

5.10

%

,

06/01/33

............

40

39,555

New

Jersey

-

0

.0

%

New

Jersey

Turnpike

Authority

,

Series

2009F

,

RB

,

7.41

%

,

01/01/40

....

8

10,004

New

York

-

0

.1

%

Metropolitan

Transportation

Authority

Series

2009A-1

,

RB

,

5.87

%

,

11/15/39

..........

10

10,261

Series

2010A

,

RB

,

6.67

%

,

11/15/39

10

11,009

New

York

City

Municipal

Water

Finance

Authority

,

Series

2010EE

,

RB

,

6.01

%

,

06/15/42

............

5

5,640

Port

Authority

of

New

York

&

New

Jersey

,

Series

2011-168

,

RB

,

4.93

%

,

10/01/51

............

15

14,949

41,859

Ohio

-

0

.0

%

American

Municipal

Power,

Inc.

,

Series

2010A

,

RB

,

8.08

%

,

02/15/50

....

10

13,477

Texas

-

0

.0

%

City

of

San

Antonio

Electric

&

Gas

Systems

,

Series

2010A

,

RB

,

5.81

%

,

02/01/41

............

10

10,866

State

of

Texas

,

Series

2009A

,

GO

,

5.52

%

,

04/01/39

............

15

16,137

27,003

Total

Municipal

Bonds

—

0.6%

(Cost:

$

325,231

)

................................

266,983

Security

Par

(000)

Pa

r

(

000)

Value

Non-Agency

Mortgage-Backed

Securities

Collateralized

Mortgage

Obligations

—

1

.1

%

United

States

—

1.1%

Alternative

Loan

Trust

(b)

Series

2006-OA6,

Class

1A1A,

(1-

mo.

CME

Term

SOFR

at

0.42%

Floor

+

0.53%),

5.89%,

07/25/46

USD

16

$

13,306

Series

2006-OC10,

Class

2A3,

(1-

mo.

CME

Term

SOFR

at

0.46%

Floor

+

0.57%),

5.93%,

11/25/36

189

152,885

Impac

Secured

Assets

Trust,

Series

2006-2,

Class

1A2B,

(1-mo.

CME

Term

SOFR

at

0.34%

Floor

and

11.50%

Cap

+

0.45%),

5.81%,

08/25/36

(b)

................

104

100,959

RFMSI

Trust,

Series

2007-SA4,

Class

3A1,

5.42%,

10/25/37

(b)

........

130

79,109

TVC

Mortgage

Trust,

Series

2023-

RTL1,

Class

A1,

8.25%,

11/25/27

(a)

(c)

100

100,666

446,925

Commercial

Mortgage-Backed

Securities

—

4

.1

%

Cayman

Islands

—

0.3%

MF1

Multifamily

Housing

Mortgage

Loan

Trust,

Series

2021-W10,

Class

G,

(1-mo.

CME

Term

SOFR

at

4.22%

Floor

+

4.22%),

9.58%,

12/15/34

(a)

(b)

...............

125

115,893

United

States

—

3.8%

1211

Avenue

of

the

Americas

Trust,

Series

2015-1211,

Class

A1A2,

3.90%,

08/10/35

(a)

...........

250

239,406

BANK,

Series

2022-BNK41,

Class

A4,

3.79%,

04/15/65

(b)

...........

80

73,379

BBCMS

Mortgage

Trust,

Series

2023-

C22,

Class

A5,

6.80%,

11/15/56

(b)

.

35

39,777

Beast

Mortgage

Trust,

Series

2021-

SSCP,

Class

A,

(1-mo.

CME

Term

SOFR

at

0.75%

Floor

+

0.86%),

6.23%,

04/15/36

(a)

(b)

..........

30

29,417

Benchmark

Mortgage

Trust,

Series

2021-B29,

Class

A5,

2.39%,

09/15/54

.................

30

24,850

BX

Commercial

Mortgage

Trust

(a)(b)

Series

2020-VKNG,

Class

A,

(1-mo.

CME

Term

SOFR

at

0.93%

Floor

+

1.04%),

6.41%,

10/15/37

...

113

112,415

Series

2022-LP2,

Class

A,

(1-mo.

CME

Term

SOFR

at

1.01%

Floor

+

1.01%),

6.37%,

02/15/39

...

49

47,720

BX

Trust,

Series

2022-IND,

Class

A,

(1-mo.

CME

Term

SOFR

at

1.49%

Floor

+

1.49%),

6.85%,

04/15/37

(a)

(b)

46

46,033

Commercial

Mortgage

Trust,

Series

2013-300P,

Class

D,

4.39%,

08/10/30

(a)

(b)

...............

25

19,466

Credit

Suisse

Mortgage

Capital

Certificates,

Series

2019-ICE4,

Class

A,

(1-mo.

CME

Term

SOFR

at

0.98%

Floor

+

1.03%),

6.39%,

05/15/36

(a)

(b)

...............

60

59,852

Grace

Trust,

Series

2020-GRCE,

Class

D,

2.68%,

12/10/40

(a)

(b)

........

250

185,594

Schedule

of

Investments

(unaudited)

(continued)

December

31,

2023

BlackRock

Sustainable

Total

Return

Fund

7

(Percentages

shown

are

based

on

Net

Assets)

Security

Par

(000)

Par

(000)

Value

United

States

(continued)

JPMorgan

Chase

Commercial

Mortgage

Securities

Trust

(a)(b)

Series

2021-MHC,

Class

D,

(1-mo.

CME

Term

SOFR

at

1.70%

Floor

+

1.81%),

7.18%,

04/15/38

...

USD

250

$

246,222

Series

2022-OPO,

Class

D,

3.45%,

01/05/39

...............

80

46,800

SUMIT

Mortgage

Trust,

Series

2022-

BVUE,

Class

D,

2.89%,

02/12/41

(a)

(b)

40

27,625

Velocity

Commercial

Capital

Loan

Trust,

Series

2021-4,

Class

M4,

4.48%,

12/26/51

(a)

(b)

..........

465

337,125

Wells

Fargo

Commercial

Mortgage

Trust

Series

2015-C26,

Class

AS,

3.58%,

02/15/48

...............

20

19,169

Series

2021-C60,

Class

A4,

2.34%,

08/15/54

...............

80

66,327

1,621,177

Interest

Only

Commercial

Mortgage-Backed

Securities

—

0

.0

%

United

States

—

0.0%

BMO

Mortgage

Trust,

Series

2023-C5,

Class

XA,

0.73%,

06/15/56

(b)

....

200

10,165

Total

Non-Agency

Mortgage-Backed

Securities

—

5.2%

(Cost:

$

2,434,958

)

..............................

2,194,160

U.S.

Government

Sponsored

Agency

Securities

Commercial

Mortgage-Backed

Securities

—

0.1%

Federal

Home

Loan

Mortgage

Corp.

Variable

Rate

Notes

,

Series

2018-

W5FX

,

Class

CFX

,

(1-mo.

LIBOR

USD

+

0.00%),

3.66

%

,

04/25/28

(a)

(b)

50

42,849

Interest

Only

Collateralized

Mortgage

Obligations

—

0.5%

Federal

Home

Loan

Mortgage

Corp.

Series

389

,

Class

C45

,

3.00

%

,

10/15/52

........

251

41,395

Series

5161

,

Class

LI

,

3.00

%

,

11/25/51

........

73

9,355

Federal

National

Mortgage

Association

Series

2021-3

,

Class

MI

,

3.50

%

,

02/25/51

........

51

8,880

Series

2021-31

,

Class

IB

,

4.00

%

,

06/25/51

........

57

11,141

Series

2023-39

,

3.00

%

,

10/25/52

97

15,645

Series

428

,

Class

C16

,

3.00

%

,

03/25/50

........

93

15,874

Series

437

,

Class

C11

,

3.00

%

,

07/25/52

........

97

15,843

Government

National

Mortgage

Association

Series

2021-58

,

Class

IY

,

3.00

%

,

02/20/51

........

70

10,631

Series

2021-78

,

Class

IP

,

3.00

%

,

05/20/51

........

74

10,873

Series

2021-97

,

Class

LI

,

3.00

%

,

08/20/50

........

63

9,515

Series

2022-78

,

Class

D

,

3.00

%

,

08/20/51

........

153

23,519

Series

2022-85

,

Class

IK

,

3.00

%

,

05/20/51

........

81

12,115

184,786

Security

Par

(000)

Par

(000)

Value

Mortgage-Backed

Securities

—

51.5%

Federal

National

Mortgage

Association

,

3.00

%

,

12/01/50

............

USD

637

$

575,681

Government

National

Mortgage

Association

2.00

%

,

08/20/50

-

11/20/50

...

105

89,181

2.50

%

,

10/20/51

-

12/20/51

...

89

77,738

3.00

%

,

03/20/52

..........

278

251,869

3.50

%

,

03/20/52

..........

60

55,663

4.00

%

,

03/20/52

..........

16

15,266

2.00

%

,

01/15/54

(e)

.........

479

405,268

2.50

%

,

01/15/54

(e)

.........

482

421,601

3.00

%

,

01/15/54

(e)

.........

142

128,283

3.50

%

,

01/15/54

(e)

.........

271

252,089

4.00

%

,

01/15/54

(e)

.........

223

212,419

4.50

%

,

01/15/54

(e)

.........

161

157,126

5.00

%

,

01/15/54

(e)

.........

156

154,903

5.50

%

,

01/15/54

(e)

.........

1,768

1,781,163

6.00

%

,

01/15/54

(e)

.........

273

277,575

6.50

%

,

01/15/54

(e)

.........

57

58,347

Uniform

Mortgage-Backed

Securities

1.50

%

,

01/25/39

-

01/25/54

(e)

..

683

562,306

2.00

%

,

01/25/39

(e)

.........

486

435,653

2.50

%

,

01/25/39

(e)

.........

221

203,579

3.00

%

,

01/25/39

-

01/25/54

(e)

..

680

608,565

3.50

%

,

01/25/39

-

01/25/54

(e)

..

935

860,252

4.50

%

,

01/25/39

-

01/25/54

(e)

..

980

950,682

4.00

%

,

12/01/44

-

06/01/52

...

2,137

2,045,611

4.50

%

,

06/01/50

..........

201

197,509

2.00

%

,

10/01/51

-

11/01/51

...

2,667

2,184,141

2.50

%

,

11/01/51

-

12/01/51

...

2,918

2,491,186

3.00

%

,

11/01/51

..........

248

223,168

3.50

%

,

11/01/51

..........

918

864,161

5.50

%

,

09/01/53

..........

295

296,044

6.00

%

,

09/01/53

..........

291

295,494

6.50

%

,

10/01/53

..........

55

56,901

5.00

%

,

01/25/54

(e)

.........

1,298

1,284,392

5.50

%

,

01/25/54

(e)

.........

873

876,683

6.00

%

,

01/25/54

(e)

.........

1,048

1,063,636

6.50

%

,

01/25/54

(e)

.........

41

42,014

7.00

%

,

01/25/54

-

02/25/54

(e)

..

1,288

1,328,315

21,784,464

Total

U.S.

Government

Sponsored

Agency

Securities

—

52

.1

%

(Cost:

$

22,800,498

)

..............................

22,012,099

U.S.

Treasury

Obligations

U.S.

Treasury

Bonds

4.50

%

,

08/15/39

............

152

161,270

1.13

%

,

05/15/40

-

08/15/40

.....

300

192,410

4.38

%

,

05/15/40

-

05/15/41

.....

102

105,405

1.38

%

,

11/15/40

............

150

99,521

4.25

%

,

11/15/40

............

130

132,509

4.75

%

,

02/15/41

............

146

157,305

1.75

%

,

08/15/41

............

150

104,320

4.00

%

,

11/15/42

-

11/15/52

.....

162

158,695

3.88

%

,

02/15/43

............

195

185,920

3.63

%

,

08/15/43

-

05/15/53

.....

170

156,267

3.75

%

,

11/15/43

............

85

79,435

2.75

%

,

11/15/47

............

218

169,682

3.00

%

,

02/15/48

-

08/15/52

.....

605

492,878

2.25

%

,

08/15/49

............

52

36,307

2.38

%

,

05/15/51

............

117

83,633

2.00

%

,

08/15/51

............

46

29,712

1.88

%

,

11/15/51

............

88

55,506

Schedule

of

Investments

(unaudited)

(continued)

December

31,

2023

BlackRock

Sustainable

Total

Return

Fund

8

(Percentages

shown

are

based

on

Net

Assets)

Security

Par

(000)

Par

(000)

Value

U.S.

Treasury

Obligations

(continued)

2.88

%

,

05/15/52

............

USD

91

$

72,452

U.S.

Treasury

Inflation

Linked

Notes

,

1.38

%

,

07/15/33

............

476

461,572

U.S.

Treasury

Notes

4.38

%

,

10/31/24

-

11/30/30

.....

50

50,325

0.75

%

,

11/15/24

............

31

29,916

1.50

%

,

02/15/25

-

01/31/27

.....

175

168,698

3.88

%

,

03/31/25

-

08/15/33

.....

602

600,476

2.63

%

,

04/15/25

............

152

148,667

0.38

%

,

04/30/25

-

09/30/27

.....

383

357,180

4.25

%

,

05/31/25

............

19

18,930

2.88

%

,

06/15/25

-

04/30/29

.....

202

196,587

0.25

%

,

06/30/25

-

07/31/25

.....

240

224,979

3.50

%

,

09/15/25

-

02/15/33

.....

325

317,799

5.00

%

,

10/31/25

............

68

68,776

4.88

%

,

11/30/25

-

10/31/30

.....

198

208,376

4.00

%

,

12/15/25

-

02/28/30

.....

252

252,031

0.50

%

,

02/28/26

-

08/31/27

.....

683

612,833

0.88

%

,

06/30/26

-

09/30/26

.....

237

218,742

0.63

%

,

07/31/26

............

52

47,631

1.13

%

,

10/31/26

............

42

38,756

1.63

%

,

11/30/26

-

05/15/31

.....

254

225,865

1.88

%

,

02/28/27

-

02/28/29

.....

159

148,957

2.75

%

,

04/30/27

-

08/15/32

.....

475

441,861

4.13

%

,

09/30/27

-

11/15/32

.....

70

70,931

1.25

%

,

03/31/28

-

08/15/31

.....

321

267,000

1.75

%

,

01/31/29

............

8

7,216

4.63

%

,

09/30/30

............

7

7,297

3.38

%

,

05/15/33

............

185

177,542

4.50

%

,

11/15/33

............

187

196,321

Total

U.S.

Treasury

Obligations

—

19.0%

(Cost:

$

8,358,579

)

..............................

8,038,491

Total

Long-Term

Investments

—

123

.1

%

(Cost:

$

53,650,139

)

..............................

52,050,608

Security

Shares

Shares

Value

Short-Term

Securities

Money

Market

Funds

—

5.6%

BlackRock

Liquidity

Funds,

T-Fund,

Institutional

Class

,

5.26

%

(f)

(g)

....

2,373,995

$

2,373,995

Total

Short-Term

Securities

—

5

.6

%

(Cost:

$

2,373,995

)

..............................

2,373,995

Total

Options

Purchased

—

0

.1

%

(Cost:

$

41,423

)

................................

52,115

Total

Investments

Before

Options

Written

and

TBA

Sale

Commitments

—

128.8%

(Cost:

$

56,065,557

)

..............................

54,476,718

Total

Options

Written

—

(

0

.4

)

%

(Premiums

Received

—

$

(

165,188

)

)

..................

(

181,578

)

Par

(000)

Pa

r

(

000)

TBA

Sale

Commitments

(e)

Government

National

Mortgage

Association

2.00

%

,

01/15/54

............

USD

(

27

)

(

22,858

)

6.00

%

,

01/15/54

............

(

170

)

(

172,849

)

Uniform

Mortgage-Backed

Securities

1.50

%

,

01/25/39

............

(

26

)

(

22,591

)

2.00

%

,

01/25/54

............

(

230

)

(

187,953

)

2.50

%

,

01/25/54

............

(

1,094

)

(

930,669

)

3.00

%

,

01/25/54

............

(

370

)

(

327,262

)

3.50

%

,

01/25/54

............

(

153

)

(

140,354

)

4.00

%

,

01/25/54

............

(

1,483

)

(

1,402,819

)

5.00

%

,

01/25/54

............

(

1,383

)

(

1,368,198

)

5.50

%

,

01/25/54

............

(

998

)

(

1,001,809

)

6.00

%

,

01/25/54

............

(

1,109

)

(

1,125,570

)

6.50

%

,

01/25/54

............

(

907

)

(

929,837

)

7.00

%

,

01/25/54

............

(

100

)

(

103,144

)

Total

TBA

Sale

Commitments

—

(

18

.3

)

%

(Proceeds:

$

(

7,618,128

)

)

..........................

(

7,735,913

)

Total

Investments

Net

of

Options

Written

and

TBA

Sale

Commitments

—

110

.1

%

(Cost:

$

48,282,241

)

..............................

46,559,227

Liabilities

in

Excess

of

Other

Assets

—

(

10.1

)

%

...........

(

4,265,535

)

Net

Assets

—

100.0%

..............................

$

42,293,692

(a)

Security

exempt

from

registration

pursuant

to

Rule

144A

under

the

Securities

Act

of

1933,

as

amended.

These

securities

may

be

resold

in

transactions

exempt

from

registration

to

qualified

institutional

investors.

(b)

Variable

rate

security.

Interest

rate

resets

periodically.

The

rate

shown

is

the

effective

interest

rate

as

of

period

end.

Security

description

also

includes

the

reference

rate

and

spread

if

published

and

available.

(c)

Step

coupon

security.

Coupon

rate

will

either

increase

(step-up

bond)

or

decrease

(step-down

bond)

at

regular

intervals

until

maturity.

Interest

rate

shown

reflects

the

rate

currently

in

effect.

(d)

This

security

may

be

resold

to

qualified

foreign

investors

and

foreign

institutional

buyers

under

Regulation

S

of

the

Securities

Act

of

1933.

(e)

Represents

or

includes

a

TBA

transaction.

(f)

Affiliate

of

the

Fund.

(g)

Annualized

7-day

yield

as

of

period

end.

Schedule

of

Investments

(unaudited)

(continued)

December

31,

2023

BlackRock

Sustainable

Total

Return

Fund

9

Affiliates

Investments

in

issuers

considered

to

be

affiliate(s)

of

the

Fund

during

the period

ended

December

31,

2023

for

purposes

of

Section

2(a)(3)

of

the

Investment

Company

Act

of

1940,

as

amended,

were

as

follows:

Affiliated

Issuer

Value

at

09/30/23

Purchases

at

Cost

Proceeds

from

Sale

Net

Realized

Gain

(Loss)

Change

in

Unrealized

Appreciation

(Depreciation)

Value

at

12/31/23

Shares

Held

at

12/31/23

Income

Capital

Gain

Distributions

from

Underlying

Funds

BlackRock

Liquidity

Funds,

T-Fund,

Institutional

Class

.

$

2,232,587

$

141,408

(a)

$

—

$

—

$

—

$

2,373,995

2,373,995

$

21,569

$

—

—

—

(a)

Represents

net

amount

purchased

(sold).

Schedule

of

Investments

(unaudited)

(continued)

December

31,

2023

BlackRock

Sustainable

Total

Return

Fund

10

Derivative

Financial

Instruments

Outstanding

as

of

Period

End

Futures

Contracts

Description

Number

of

Contracts

Expiration

Date

Notional

Amount

(000)

Value/

Unrealized

Appreciation

(Depreciation)

Long

Contracts

Australia

10-Year

Bond

......................................................

2

03/15/24

$

159

$

4,392

U.S.

Treasury

10-Year

Note

...................................................

4

03/19/24

452

248

U.S.

Treasury

Long

Bond

.....................................................

7

03/19/24

875

13,850

U.S.

Treasury

Ultra

Bond

.....................................................

6

03/19/24

802

63,610

U.S.

Treasury

5-Year

Note

....................................................

32

03/28/24

3,481

50,050

3-mo.

SOFR

.............................................................

9

06/18/24

2,138

4,395

136,545

Short

Contracts

Euro-Bobl

...............................................................

5

03/07/24

658

(

9,669

)

Euro-Bund

..............................................................

3

03/07/24

454

(

10,499

)

Euro-Buxl

...............................................................

1

03/07/24

156

(

12,770

)

Euro-Schatz

.............................................................

7

03/07/24

823

(

5,725

)

Canada

10-Year

Bond

.......................................................

6

03/19/24

562

(

26,631

)

U.S.

Treasury

10-Year

Ultra

Note

...............................................

6

03/19/24

708

(

6,574

)

U.S.

Treasury

2-Year

Note

....................................................

15

03/28/24

3,089

(

4,347

)

3-mo.

SOFR

.............................................................

16

12/17/24

3,836

(

16,742

)

3-mo.

SOFR

.............................................................

9

06/17/25

2,173

(

10,454

)

(

103,411

)

$

33,134

Forward

Foreign

Currency

Exchange

Contracts

Currency

Purchased

Currency

Sold

Counterparty

Settlement

Date

Unrealized

Appreciation  

(Depreciation)

USD

5,510

EUR

5,000

HSBC

Bank

plc

03/20/24

$

(

27

)

USD

2,231,939

EUR

2,034,000

UBS

AG

03/20/24

(

20,494

)

$

(

20,521

)

Exchange-Traded

Options

Purchased

Description

Number

of

Contracts

Expiration

Date

Exercise

Price

Notional

Amount

(000)

Value

Call

3-mo.

SOFR

Interest

Futures

....................

45

03/15/24

USD

94.94

USD

11,250

$

18,281

OTC

Interest

Rate

Swaptions

Purchased

Paid

by

the

Fund

Received

by

the

Fund

Description

Rate

Frequency

Rate

Frequency

Counterparty

Expiration

Date

Exercise

Rate

Notional

Amount

(000)

Value

Call

5-Year

Interest

Rate

Swap

(a)

.

1-day

SOFR

Annual

4.24%

Semi-Annual

Citibank

NA

03/26/24

4

.24

%

USD

794

$

29,163

Put

10-Year

Interest

Rate

Swap

(a)

2.83%

Annual

6-mo.

EURIBOR

Semi-Annual

JPMorgan

Chase

Bank

NA

03/12/24

2

.83

EUR

596

3,569

Schedule

of

Investments

(unaudited)

(continued)

December

31,

2023

BlackRock

Sustainable

Total

Return

Fund

11

OTC

Interest

Rate

Swaptions

Purchased

(continued)

Paid

by

the

Fund

Received

by

the

Fund

Description

Rate

Frequency

Rate

Frequency

Counterparty

Expiration

Date

Exercise

Rate

Notional

Amount

(000)

Value

5-Year

Interest

Rate

Swap

(a)

.

4.24%

Semi-Annual

1-day

SOFR

Annual

Citibank

NA

03/26/24

4

.24

%

USD

794

$

1,102

4,671

$

33,834

(a)

Forward

settling

swaption.

Exchange-Traded

Options

Written

Description

Number

of

Contracts

Expiration

Date

Exercise

Price

Notional

Amount

(000)

Value

Call

3-mo.

SOFR

Interest

Futures

.....................

22

03/15/24

USD

96.50

USD

5,500

$

(

18,563

)

OTC

Interest

Rate

Swaptions

Written

Paid

by

the

Fund

Received

by

the

Fund

Description

Rate

Frequency

Rate

Frequency

Counterparty

Expiration

Date

Exercise

Rate

Notional

Amount

(000)

Value

Call

5-Year

Interest

Rate

Swap

(a)

.

3.96%

Semi-Annual

1-day

SOFR

Annual

Barclays

Bank

plc

03/14/24

3

.96

%

USD

794

$

(

19,961

)

5-Year

Interest

Rate

Swap

(a)

.

3.75%

Annual

1-day

SOFR

Annual

Citibank

NA

06/12/24

3

.75

USD

1,985

(

50,969

)

5-Year

Interest

Rate

Swap

(a)

.

3.90%

Semi-Annual

1-day

SOFR

Annual

Deutsche

Bank

AG

11/14/24

3

.90

USD

553

(

20,511

)

10-Year

Interest

Rate

Swap

(a)

4.48%

Semi-Annual

1-day

SOFR

Annual

JPMorgan

Chase

Bank

NA

10/20/25

4

.48

USD

32

(

3,307

)

10-Year

Interest

Rate

Swap

(a)

4.54%

Semi-Annual

1-day

SOFR

Annual

JPMorgan

Chase

Bank

NA

10/20/25

4

.54

USD

31

(

3,337

)

10-Year

Interest

Rate

Swap

(a)

3.96%

Semi-Annual

1-day

SOFR

Annual

Deutsche

Bank

AG

11/17/25

3

.96

USD

32

(

2,385

)

10-Year

Interest

Rate

Swap

(a)

4.00%

Semi-Annual

1-day

SOFR

Annual

Bank

of

America

NA

11/17/25

4

.00

USD

58

(

4,376

)

10-Year

Interest

Rate

Swap

(a)

3.97%

Semi-Annual

1-day

SOFR

Annual

Citibank

NA

11/20/25

3

.97

USD

49

(

3,602

)

10-Year

Interest

Rate

Swap

(a)

3.90%

Semi-Annual

1-day

SOFR

Annual

Morgan

Stanley

&

Co.

International

plc

11/24/25

3

.90

USD

24

(

1,708

)

10-Year

Interest

Rate

Swap

(a)

3.84%

Semi-Annual

1-day

SOFR

Annual

Bank

of

America

NA

11/28/25

3

.84

USD

37

(

2,468

)

10-Year

Interest

Rate

Swap

(a)

3.87%

Semi-Annual

1-day

SOFR

Annual

Bank

of

America

NA

11/28/25

3

.87

USD

24

(

1,674

)

10-Year

Interest

Rate

Swap

(a)

3.96%

Semi-Annual

1-day

SOFR

Annual

Citibank

NA

11/28/25

3

.96

USD

41

(

3,052

)

10-Year

Interest

Rate

Swap

(a)

3.67%

Annual

1-day

SOFR

Annual

Deutsche

Bank

AG

12/05/25

3

.67

USD

24

(

1,468

)

10-Year

Interest

Rate

Swap

(a)

3.71%

Annual

1-day

SOFR

Annual

Bank

of

America

NA

12/11/25

3

.71

USD

61

(

3,791

)

10-Year

Interest

Rate

Swap

(a)

3.40%

Annual

1-day

SOFR

Annual

Morgan

Stanley

&

Co.

International

plc

12/15/25

3

.40

USD

25

(

1,180

)

10-Year

Interest

Rate

Swap

(a)

4.17%

Semi-Annual

1-day

SOFR

Annual

JPMorgan

Chase

Bank

NA

09/28/26

4

.17

USD

33

(

2,923

)

(

126,712

)

Put

10-Year

Interest

Rate

Swap

(a)

6-mo.

EURIBOR

Semi-Annual

3.23%

Annual

JPMorgan

Chase

Bank

NA

03/12/24

3

.23

EUR

596

(

1,053

)

5-Year

Interest

Rate

Swap

(a)

.

1-day

SOFR

Annual

3.96%

Semi-Annual

Barclays

Bank

plc

03/14/24

3

.96

USD

794

(

2,149

)

5-Year

Interest

Rate

Swap

(a)

.

1-day

SOFR

Annual

3.75%

Annual

Citibank

NA

06/12/24

3

.75

USD

1,985

(

14,863

)

5-Year

Interest

Rate

Swap

(a)

.

1-day

SOFR

Annual

3.90%

Semi-Annual

Deutsche

Bank

AG

11/14/24

3

.90

USD

553

(

4,879

)

10-Year

Interest

Rate

Swap

(a)

1-day

SOFR

Annual

4.48%

Semi-Annual

JPMorgan

Chase

Bank

NA

10/20/25

4

.48

USD

32

(

530

)

10-Year

Interest

Rate

Swap

(a)

1-day

SOFR

Annual

4.54%

Semi-Annual

JPMorgan

Chase

Bank

NA

10/20/25

4

.54

USD

31

(

492

)

10-Year

Interest

Rate

Swap

(a)

1-day

SOFR

Annual

3.96%

Semi-Annual

Deutsche

Bank

AG

11/17/25

3

.96

USD

32

(

882

)

10-Year

Interest

Rate

Swap

(a)

1-day

SOFR

Annual

4.00%

Semi-Annual

Bank

of

America

NA

11/17/25

4

.00

USD

58

(

1,509

)

10-Year

Interest

Rate

Swap

(a)

1-day

SOFR

Annual

3.97%

Semi-Annual

Citibank

NA

11/20/25

3

.97

USD

49

(

1,317

)

10-Year

Interest

Rate

Swap

(a)

1-day

SOFR

Annual

3.90%

Semi-Annual

Morgan

Stanley

&

Co.

International

plc

11/24/25

3

.90

USD

24

(

698

)

Schedule

of

Investments

(unaudited)

(continued)

December

31,

2023

BlackRock

Sustainable

Total

Return

Fund

12

OTC

Interest

Rate

Swaptions

Written

(continued)

Paid

by

the

Fund

Received

by

the

Fund

Description

Rate

Frequency

Rate

Frequency

Counterparty

Expiration

Date

Exercise

Rate

Notional

Amount

(000)

Value

10-Year

Interest

Rate

Swap

(a)

1-day

SOFR

Annual

3.84%

Semi-Annual

Bank

of

America

NA

11/28/25

3

.84

%

USD

37

$

(

1,110

)

10-Year

Interest

Rate

Swap

(a)

1-day

SOFR

Annual

3.87%

Semi-Annual

Bank

of

America

NA

11/28/25

3

.87

USD

24

(

717

)

10-Year

Interest

Rate

Swap

(a)

1-day

SOFR

Annual

3.96%

Semi-Annual

Citibank

NA

11/28/25

3

.96

USD

41

(

1,139

)

10-Year

Interest

Rate

Swap

(a)

1-day

SOFR

Annual

3.67%

Annual

Deutsche

Bank

AG

12/05/25

3

.67

USD

24

(

850

)

10-Year

Interest

Rate

Swap

(a)

1-day

SOFR

Annual

3.71%

Annual

Bank

of

America

NA

12/11/25

3

.71

USD

61

(

2,050

)

10-Year

Interest

Rate

Swap

(a)

1-day

SOFR

Annual

3.40%

Annual

Morgan

Stanley

&

Co.

International

plc

12/15/25

3

.40

USD

25

(

1,075

)

10-Year

Interest

Rate

Swap

(a)

1-day

SOFR

Annual

4.17%

Semi-Annual

JPMorgan

Chase

Bank

NA

09/28/26

4

.17

USD

33

(

990

)

(

36,303

)

$

(

163,015

)

(a)

Forward

settling

swaption.

Centrally

Cleared

Interest

Rate

Swap

s

Paid

by

the

Fund

Received

by

the

Fund

Rate

Frequency

Rate

Frequency

Effective

Date

Termination

Date

Notional

Amount

(000)

Value

Upfront

Premium

Paid

(Received)

Unrealized

Appreciation

(Depreciation)

6-mo.

EURIBOR

Semi-Annual

3.53%

Annual

N/A

11/08/25

EUR

360

$

4,213

$

—

$

4,213

6-mo.

EURIBOR

Semi-Annual

3.54%

Annual

N/A

11/08/25

EUR

360

4,262

—

4,262

3.16%

Annual

6-mo.

EURIBOR

Semi-Annual

N/A

11/08/28

EUR

300

(

10,265

)

—

(

10,265

)

3.16%

Annual

6-mo.

EURIBOR

Semi-Annual

N/A

11/08/28

EUR

300

(

10,382

)

—

(

10,382

)

1-day

SOFR

Annual

3.33%

Annual

06/17/24

(a)

06/17/29

USD

160

(

71

)

—

(

71

)

1-day

SOFR

Annual

3.36%

Annual

06/17/24

(a)

06/17/29

USD

120

118

—

118

1-day

SOFR

Annual

3.41%

Annual

06/17/24

(a)

06/17/29

USD

240

724

—

724

1-day

SOFR

Annual

3.42%

Annual

06/17/24

(a)

06/17/29

USD

90

338

—

338

1-day

SOFR

Annual

3.44%

Annual

06/17/24

(a)

06/17/29

USD

120

528

—

528

1-day

REPO_CORRA

Semi-Annual

3.54%

Semi-Annual

N/A

06/15/33

CAD

133

3,815

—

3,815

1-day

REPO_CORRA

Semi-Annual

4.00%

Semi-Annual

N/A

09/21/33

CAD

35

1,979

—

1,979

6-mo.

EURIBOR

Semi-Annual

3.22%

Annual

N/A

11/08/33

EUR

81

5,539

—

5,539

6-mo.

EURIBOR

Semi-Annual

3.22%

Annual

N/A

11/08/33

EUR

81

5,602

—

5,602

3.40%

Semi-Annual

1-day

REPO_CORRA

Semi-Annual

N/A

06/15/53

CAD

59

(

3,728

)

—

(

3,728

)

3.72%

Semi-Annual

1-day

REPO_CORRA

Semi-Annual

N/A

09/21/53

CAD

15

(

1,628

)

—

(

1,628

)

$

1,044

$

—

$

1,044

(a)

Forward

swap.

OTC

Credit

Default

Swap

s

—

Buy

Protection

Reference

Obligation/Index

Financing

Rate

Paid

by

the

Fund

Payment

Frequency

Counterparty

Termination

Date

Notional

Amount

(000)

Value

Upfront

Premium

Paid

(Received)

Unrealized

Appreciation

(Depreciation)

Abbott

Laboratories

........

1

.00

%

Quarterly

JPMorgan

Chase

Bank

NA

12/20/28

USD

17

$

(

414

)

$

(

319

)

$

(

95

)

$

–

$

–

$

–

Schedule

of

Investments

(unaudited)

(continued)

December

31,

2023

BlackRock

Sustainable

Total

Return

Fund

13

Fair

Value

Hierarchy

as

of

Period

End

Various

inputs

are

used

in

determining

the

fair

value

of

financial

instruments.

These

inputs

to

valuation

techniques

are

categorized

into

a

fair

value

hierarchy

consisting

of

three

broad

levels

for

financial

reporting

purposes

as

follows:

Level

1

—

Unadjusted

price

quotations

in

active

markets/exchanges

for

identical

assets

or

liabilities

that

the

Fund

has

the

ability

to

access;

Level

2

—

Other

observable

inputs

(including,

but

not

limited

to,

quoted

prices

for

similar

assets

or

liabilities

in

markets

that

are

active,

quoted

prices

for

identical

or

similar

assets

or

liabilities

in

markets

that

are

not

active,

inputs

other

than

quoted

prices

that

are

observable

for

the

assets

or

liabilities

(such

as

interest

rates,

yield

curves,

volatilities,

prepayment

speeds,

loss

severities,

credit

risks

and

default

rates)

or

other

market-corroborated

inputs);

and

Level

3

—

Unobservable

inputs

based

on

the

best

information

available

in

the

circumstances,

to

the

extent

observable

inputs

are

not

available

(including

the

Valuation

Committee's

assumptions

used

in

determining

the

fair

value

of

financial

instruments).

The

hierarchy

gives

the

highest

priority

to

unadjusted

quoted

prices

in

active

markets

for

identical

assets

or

liabilities

(Level

1

measurements)

and

the

lowest

priority

to

unobservable

inputs

(Level

3

measurements).

Accordingly,

the

degree

of

judgment

exercised

in

determining

fair

value

is

greatest

for

instruments

categorized

in

Level

3.

The

inputs

used

to

measure

fair

value

may

fall

into

different

levels

of

the

fair

value

hierarchy.

In

such

cases,

for

disclosure

purposes,

the

fair

value

hierarchy

classification

is

determined

based

on

the

lowest

level

input

that

is

significant

to

the

fair

value

measurement

in

its

entirety.

Investments

classified

within

Level

3

have

significant

unobservable

inputs

used

by

the

Valuation

Committee

in

determining

the

price

for

Fair

Valued

Investments.

Level

3

investments

include

equity

or

debt

issued

by

privately

held

companies

or

funds.

There

may

not

be

a

secondary

market,

and/

or

there

are

a

limited

number

of

investors.

The

categorization

of

a

value

determined

for

financial

instruments

is

based

on

the

pricing

transparency

of

the

financial

instruments

and

is

not

necessarily

an

indication

of

the

risks

associated

with

investing

in

those

securities.

For

information

about

the

Fund’s

policy

regarding

valuation

of

financial

instruments,

refer

to

its

most

recent

financial

statements.

The

following

table

summarizes

the

Fund’s

financial

instruments

categorized

in

the

fair

value

hierarchy.

The

breakdown

of

the

Fund's

financial

instruments

into

major

categories

is

disclosed

in

the

Schedule

of

Investments

above.

The

following

reference

rates,

and

their

values

as

of

period

end,

are

used

for

security

descriptions:

Reference

Index

Reference

Rate

1-day

REPO_CORRA

...................................

Canadian

Overnight

Repo

Rate

5

.06

%

1-day

SOFR

.........................................

Secured

Overnight

Financing

Rate

5

.34

6-mo.

EURIBOR

......................................

Euro

Interbank

Offered

Rate

3

.86

Level

1

Level

2

Level

3

Total

Assets

Investments

Long-Term

Investments

Asset-Backed

Securities

...................................

$

—

$

5,338,294

$

—

$

5,338,294

Corporate

Bonds

........................................

—

13,239,962

—

13,239,962

Foreign

Agency

Obligations

.................................

—

383,118

—

383,118

Foreign

Government

Obligations

..............................

—

577,501

—

577,501

Municipal

Bonds

.........................................

—

266,983

—

266,983

Non-Agency

Mortgage-Backed

Securities

........................

—

2,194,160

—

2,194,160

U.S.

Government

Sponsored

Agency

Securities

....................

—

22,012,099

—

22,012,099

U.S.

Treasury

Obligations

...................................

—

8,038,491

—

8,038,491

Short-Term

Securities

Money

Market

Funds

......................................

2,373,995

—

—

2,373,995

Options

Purchased

Interest

rate

contracts

......................................

18,281

33,834

—

52,115

Liabilities

Investments

TBA

Sale

Commitments

....................................

—

(

7,735,913

)

—

(

7,735,913

)

$

2,392,276

$

44,348,529

$

—

$

46,740,805

Derivative

Financial

Instruments

(a)

Assets

Interest

rate

contracts

.......................................

$

136,545

$

27,118

$

—

$

163,663

Liabilities

Credit

contracts

...........................................

—

(

95

)

—

(

95

)

Foreign

currency

exchange

contracts

............................

—

(

20,521

)

—

(

20,521

)

Interest

rate

contracts

.......................................

(

121,974

)

(

189,089

)

—

(

311,063

)

$

14,571

$

(

182,587

)

$

—

$

(

168,016

)

Schedule

of

Investments

(unaudited)

(continued)

December

31,

2023

BlackRock

Sustainable

Total

Return

Fund

14

(a)

Derivative

financial

instruments

are

swaps,

futures

contracts,

forward

foreign

currency

exchange

contracts

and

options

written.

Swaps,

futures

contracts

and

forward

foreign

currency

exchange

contracts

are

valued

at

the

unrealized

appreciation

(depreciation)

on

the

instrument

and

options

written

are

shown

at

value.

Currency

Abbreviation

CAD

Canadian

Dollar

EUR

Euro

MXN

Mexican

Peso

USD

United

States

Dollar

Portfolio

Abbreviation

CLO

Collateralized

Loan

Obligation

DAC

Designated

Activity

Company

EURIBOR

Euro

Interbank

Offered

Rate

GO

General

Obligation

Bonds

LIBOR

London

Interbank

Offered

Rate

MSCI

Morgan

Stanley

Capital

International

OTC

Over-the-counter

RB

Revenue

Bonds

REIT

Real

Estate

Investment

Trust

REPO_CORRA

Canadian

Overnight

Repo

Rate

SOFR

Secured

Overnight

Financing

Rate

TBA

To-be-announced

Fair

Value

Hierarchy

as

of

Period

End

(continued)