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)