iShares Trust - iShares MBS ETF
US ˙ NasdaqGM ˙ US4642885887

SecurityMBB / iShares Trust - iShares MBS ETF
InstitutionCitigroup Inc
Latest Disclosed Ownership32,239 shares
Latest Disclosed Value $ 3,061,129
Citigroup Inc ownership in MBB / iShares Trust - iShares MBS ETF

On May 11, 2026 - Citigroup Inc filed a 13F-HR form disclosing ownership of 32,239 shares of iShares Trust - iShares MBS ETF (US:MBB) valued at $3,061,093 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 13, 2026 disclosing 127,984 shares of iShares Trust - iShares MBS ETF. This represents a change in shares of -74.81% during the quarter. The current value of the position is $3,037,236 USD.

Citigroup Inc has a history of taking positions in derivatives of the underlying security (MBB) in the form of stock options. The firm currently holds call options representing 0 of underlying shares valued at $0 USD .

Note: prior versions of this page mistakenly stated that the share values represented the number of options, not the number of underlying shares. For more information on the data backing these reports, please see the SEC document Frequently Asked Questions About Form 13F.

Institutional Ownership: 13F and NPORT Filings

The Security and Class in the table below are shown exactly as filed by the investor. We do our best to track continuity of investments through acquisitions, and this will be reflected in the table as changes in names. In addition to descriptive data, performance of the investment is shown over time. To calculate quarterly performance, we first calculate cost basis of the shares purchased during the quarter, then use that to calculate gross profit. Quarterly return is Gross Profit / Starting Portfolio value.

Note that cost basis is calculated and stored in thousands, so small quarterly changes in shares frequently result in a cost basis of zero.

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Institutional Put/Call Ratios
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In addition to reporting standard equity and debt issues, institutions with more than 100MM assets under management must also disclose their put and call option holdings. Since put options generally indicate negative sentiment, and call options indicate positive sentiment, we can get a sense of the overall institutional sentiment by plotting the ratio of puts to calls. The chart to the right plots the historical put/call ratio for this instrument.

Using Put/Call Ratio as an indicator of investor sentiment overcomes one of the key deficiencies of using total institutional ownership, which is that a significant amount of assets under management are invested passively to track indices. Passively-managed funds do not typically buy options, so the put/call ratio indicator more closely tracks the sentiment of actively-managed funds.

MBB / iShares Trust - iShares MBS ETF Historical Put/Call Ratio
Disclosed Equity Positions (from 13F/NPORT Filings)
File
Date
Effective
Date
Form Security Class ID Avg Price
Paid (Est)
Reported
Shares
ΔShares ΔShares
(%)
Reported
Value
(x1000)
ΔValue
(%)
Alloc
(%)
ΔAlloc ΔAlloc (%) Cost Basis
(x1000)
Unrealized
Gain/Loss
(x1000)
2026-05-11 2026-03-31 13F ISHARES TR MBS ETF 464288588 32,239 -95,745 -74.81 3,061 -74.88 0.0013
2026-02-13 2025-12-31 13F ISHARES TR MBS ETF 464288588 127,984 102,681 405.81 12,187 406.27 0.0054
2025-11-10 2025-09-30 13F ISHARES TR MBS ETF 464288588 25,303 1,560 6.57 2,408 7.99 0.0011
2025-08-11 2025-06-30 13F ISHARES TR MBS ETF 464288588 23,743 -82,205 -77.59 2,229 -77.56 0.0011
2025-05-12 2025-03-31 13F ISHARES TR MBS ETF 464288588 105,948 100,350 1,792.60 9,936 1,836.65 0.0051
2025-02-12 2024-12-31 13F ISHARES TR MBS ETF 464288588 5,598 -17,327 -75.58 513 -76.64 0.0003
2024-11-12 2024-09-30 13F ISHARES TR MBS ETF 464288588 22,925 19,073 495.15 2,196 522.10 0.0013
2024-08-12 2024-06-30 13F ISHARES TR MBS ETF 464288588 3,852 554 16.80 354 16.12 0.0002
2024-05-10 2024-03-31 13F ISHARES TR MBS ETF 464288588 3,298 -1,567 -32.21 305 -33.48 0.0002
2024-02-09 2023-12-31 13F ISHARES TR MBS ETF 464288588 4,865 579 13.51 458 20.26 0.0003
2023-12-06 2023-09-30 13F/A-1 ISHARES TR MBS ETF 464288588 4,286 -1,027 -19.33 381 -23.23 0.0003
2023-11-09 2023-09-30 13F ISHARES TR MBS ETF 464288588 4,286 -1,027 381 0.0001
2023-08-10 2023-06-30 13F ISHARES TR MBS ETF 464288588 5,313 2,458 86.09 496 83.33 0.0003
2023-05-11 2023-03-31 13F ISHARES TR MBS ETF 464288588 2,855 373 15.03 270 17.39 0.0002
2023-02-09 2022-12-31 13F ISHARES TR MBS ETF 464288588 2,482 345 16.14 230 17.35 0.0002
2022-11-10 2022-09-30 13F ISHARES TR MBS ETF 464288588 2,137 -117 -5.19 196 -10.91 0.0001
2022-08-10 2022-06-30 13F ISHARES TR MBS ETF 464288588 2,254 -276 -10.91 220 -14.73 0.0002
2022-05-12 2022-03-31 13F ISHARES TR MBS ETF 464288588 2,530 -141 -5.28 258 -10.10 0.0002
2022-02-10 2021-12-31 13F ISHARES TR MBS ETF 464288588 2,671 -23,126 -89.65 287 -89.71 0.0002
2021-11-10 2021-09-30 13F ISHARES TR MBS ETF 464288588 25,797 8,707 50.95 2,790 50.81 0.0016
2021-08-10 2021-06-30 13F ISHARES TR MBS ETF 464288588 17,090 -18,323 -51.74 1,850 -51.82 0.0011
2021-05-13 2021-03-31 13F ISHARES TR MBS ETF 464288588 35,413 737 2.13 3,840 0.58 0.0025
2021-02-11 2020-12-31 13F ISHARES TR MBS ETF 464288588 34,676 -5,393 -13.46 3,818 -13.68 0.0023
2020-11-12 2020-09-30 13F ISHARES TR MBS ETF 464288588 40,069 17,864 80.45 4,423 79.94 0.0029
2020-08-12 2020-06-30 13F ISHARES TR MBS ETF 464288588 22,205 -854 -3.70 2,458 -3.49 0.0019
2020-05-12 2020-03-31 13F ISHARES TR MBS ETF 464288588 23,059 5,139 28.68 2,547 31.56 0.0023
2020-02-12 2019-12-31 13F ISHARES TR MBS ETF 464288588 17,920 -6,274 -25.93 1,936 -26.11 0.0014
2019-11-08 2019-09-30 13F ISHARES TR MBS ETF 464288588 24,194 -803 -3.21 2,620 -2.60 0.0021
2019-08-12 2019-06-30 13F ISHARES TR MBS ETF 464288588 24,997 -1,832 -6.83 2,690 -5.75 0.0022
2019-05-13 2019-03-31 13F ISHARES TR MBS ETF 464288588 26,829 1,429 5.63 2,854 7.37 0.0028
2019-02-12 2018-12-31 13F ISHARES TR MBS ETF 464288588 25,400 22,247 705.58 2,658 715.34 0.0027
2018-11-13 2018-09-30 13F ISHARES TR MBS ETF 464288588 3,153 -15,250 -82.87 326 -82.99 0.0003
2018-08-10 2018-06-30 13F ISHARES TR MBS ETF 464288588 18,403 16,729 999.34 1,917 995.43 0.0018
2018-05-11 2018-03-31 13F ISHARES TR MBS ETF 464288588 1,674 -2,867 -63.14 175 -63.84 0.0001
2018-02-12 2017-12-31 13F ISHARES TR MBS ETF 464288588 4,541 274 6.42 484 5.91 0.0004
2017-11-13 2017-09-30 13F ISHARES TR MBS ETF 464288588 4,267 3,177 291.47 457 293.97 0.0004
2017-08-11 2017-06-30 13F ISHARES TR MBS ETF 464288588 1,090 101 10.21 116 10.48 0.0001
2017-05-12 2017-03-31 13F ISHARES TR MBS ETF 464288588 989 231 30.47 105 29.63 0.0001
2017-02-10 2016-12-31 13F ISHARES TR MBS ETF 464288588 758 33 4.55 81 1.25 0.0001
2016-11-10 2016-09-30 13F ISHARES TR MBS ETF 464288588 725 -312 -30.09 80 -29.82 0.0001
2016-08-12 2016-06-30 13F ISHARES TR MBS ETF 464288588 1,037 644 163.87 114 165.12 0.0001
2016-05-13 2016-03-31 13F ISHARES TR MBS ETF 464288588 393 70 21.67 43 22.86 0.0000
2016-02-12 2015-12-31 13F ISHARES TR MBS ETF 464288588 323 -1,340 -80.58 35 -80.77 0.0000
2015-11-13 2015-09-30 13F ISHARES TR MBS ETF 464288588 1,663 -236 -12.43 182 -12.08 0.0002
2015-08-13 2015-06-30 13F ISHARES MBS ETF 464288588 1,899 313 19.74 207 18.29 0.0002
2015-05-14 2015-03-31 13F ISHARES MBS ETF 464288588 1,586 -1,918 -54.74 175 -54.31 0.0002
2015-02-17 2014-12-31 13F ISHARES MBS ETF 464288588 3,504 695 24.74 383 26.40 0.0003
2014-11-14 2014-09-30 13F ISHARES MBS ETF 464288588 2,809 -1,282 -31.34 303 -31.45 0.0003
2014-08-14 2014-06-30 13F ISHARES MBS ETF 464288588 4,091 -3,008 -42.37 442 -41.30 0.0004
2014-05-15 2014-03-31 13F ISHARES MBS ETF 464288588 7,099 603 9.28 753 10.90 0.0008
2014-02-14 2013-12-31 13F ISHARES MBS ETF 464288588 6,496 1,051 19.30 679 17.68 0.0006
2013-11-14 2013-09-30 13F ISHARES MBS ETF 464288588 5,445 4,235 350.00 577 354.33 0.0005
2013-08-14 2013-06-30 13F ISHARES TR BARCLYS MBS BD 464288588 1,210 1,210 127 0.0001
Disclosed Call Options
File
Date
Effective
Date
Form Security Class ID Opt Avg Share
Price
Shares ΔShares
(%)
Value
(x1000)
ΔValue
(%)
Prior Allocation
(%)
Allocation
(%)
ΔAllocation
(%)
Cost Basis
(x1000)
Profit
(x1000)
Return
(%)
2023-02-09 2022-12-31 13F ISHARES TR MBS ETF Call 0 -100.00 0 -100.00 n/a n/a n/a
2022-11-10 2022-09-30 13F ISHARES TR MBS ETF Call 1,000,000 91,580 n/a n/a n/a
Legend
Shares
The total number of shares held by the institution at the end of the reporting period (the effective date). This is provided in the filing.
Value
The total value of the shares as of the effective date. This is provided in the filing.
Avg. Share Price
The weighted average share price of the shares held by the institution. We use FIFO accounting to determine this price
Class
This is the security class as indicated by the filer. There are a variety of values for this field. Common values include "EC" = equity common, "EP" - equity preferred
Allocation (%)
The percent of the institution's portfolio that this position represents. This is provided in NPORT filings. For 13F filings, we calculate it.
Change in Allocation
The change in allocation from the prior reporting period. This is calculated as current allocation - prior allocation.
Change in Allocation (%)
The percent change in allocation from the prior reporting period. This is calculated as (current allocation - prior allocation) / prior allocation.
Cost Basis
The total cost of the shares held. This is calculated as reported shares * avg. share price
Unrealized Gain/Loss
This is the market value of the position as of the effective date minus the cost basis.