iShares Trust - iShares MBS ETF
US ˙ NasdaqGM ˙ US4642885887

SecurityMBB / iShares Trust - iShares MBS ETF
InstitutionSei Investments Co
Latest Disclosed Ownership2,086,086 shares
Latest Disclosed Value $ 198,638,286
Sei Investments Co ownership in MBB / iShares Trust - iShares MBS ETF

On February 13, 2026 - Sei Investments Co filed a 13F-HR form disclosing ownership of 2,086,086 shares of iShares Trust - iShares MBS ETF (US:MBB) valued at $198,637,109 USD as of December 31, 2025. The entity filed a previous 13F-HR on November 13, 2025 disclosing 2,176,254 shares of iShares Trust - iShares MBS ETF. This represents a change in shares of -4.14% during the quarter. The current value of the position is $196,530,162 USD.

Sei Investments Co has a history of taking positions in derivatives of the underlying security (MBB) in the form of stock options.

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)
2026-02-13 2025-12-31 13F ISHARES TR MBS ETF 464288588 2,086,086 -90,168 -4.14 198,638 -4.08 0.1961
2025-11-13 2025-09-30 13F ISHARES TR MBS ETF 464288588 2,176,254 240,833 12.44 207,079 13.95 0.2227
2025-08-14 2025-06-30 13F ISHARES TR MBS ETF 464288588 1,935,421 -112,091 -5.47 181,725 -5.36 0.2106
2025-05-14 2025-03-31 13F/A-1 ISHARES TR MBS ETF 464288588 2,047,512 -9,663 -0.47 192,018 1.81 0.2471
2025-05-13 2025-03-31 13F ISHARES TR MBS ETF 464288588 2,047,512 -9,663 189,778 0.2064
2025-02-11 2024-12-31 13F ISHARES TR MBS ETF 464288588 2,057,175 147,930 7.75 188,613 3.11 0.2422
2024-11-12 2024-09-30 13F ISHARES TR MBS ETF 464288588 1,909,245 -478,511 -20.04 182,921 -16.56 0.2375
2024-08-13 2024-06-30 13F ISHARES TR MBS ETF 464288588 2,387,756 411,096 20.80 219,222 20.00 0.3106
2024-05-07 2024-03-31 13F ISHARES TR MBS ETF 464288588 1,976,660 100,010 5.33 182,683 3.47 0.2677
2024-02-14 2023-12-31 13F ISHARES TR MBS ETF 464288588 1,876,650 34,864 1.89 176,554 7.95 0.2834
2023-11-14 2023-09-30 13F ISHARES TR MBS ETF 464288588 1,841,786 131,566 7.69 163,551 2.53 0.2939
2023-08-11 2023-06-30 13F ISHARES TR MBS ETF 464288588 1,710,220 1,375,889 411.53 159,511 403.65 0.2782
2023-05-12 2023-03-31 13F ISHARES TR MBS ETF 464288588 334,331 -4,721 -1.39 31,671 0.71 0.0588
2023-02-10 2022-12-31 13F ISHARES TR MBS ETF 464288588 339,052 13,318 4.09 31,447 5.42 0.0699
2022-11-14 2022-09-30 13F ISHARES TR MBS ETF 464288588 325,734 -1,017 -0.31 29,831 -6.34 0.0665
2022-08-15 2022-06-30 13F ISHARES TR MBS ETF 464288588 326,751 2,825 0.87 31,851 -3.47 0.0688
2022-05-13 2022-03-31 13F ISHARES TR MBS ETF 464288588 323,926 12,332 3.96 32,997 -1.43 0.0663
2022-02-14 2021-12-31 13F ISHARES TR MBS ETF 464288588 311,594 15,036 5.07 33,477 4.38 0.0628
2021-11-12 2021-09-30 13F ISHARES TR MBS ETF 464288588 296,558 50,114 20.33 32,073 20.29 0.0673
2021-08-06 2021-06-30 13F ISHARES TR MBS ETF 464288588 246,444 2,455 1.01 26,664 0.79 0.0591
2021-05-12 2021-03-31 13F ISHARES TR MBS ETF 464288588 243,989 -130,821 -34.90 26,454 -35.91 0.0667
2021-02-08 2020-12-31 13F ISHARES TR MBS ETF 464288588 374,810 8,139 2.22 41,277 1.96 0.1067
2020-12-04 2020-09-30 13F/A-1 ISHARES TR MBS ETF 464288588 366,671 -38,416 -9.48 40,483 -9.73 0.1172
2020-11-06 2020-09-30 13F ISHARES TR MBS ETF 464288588 366,727 -38,360 40,489 97,488.5097
2020-08-17 2020-06-30 13F/A-1 ISHARES TR MBS ETF 464288588 405,087 35,255 9.53 44,845 9.81 0.1392
2020-08-11 2020-06-30 13F ISHARES TR MBS ETF 464288588 328,835 -40,997 35,545 96,417.7046
2020-05-14 2020-03-31 13F ISHARES TR MBS ETF 464288588 369,832 42,408 12.95 40,837 15.43 0.1500
2020-02-06 2019-12-31 13F ISHARES TR MBS ETF 464288588 327,424 36,377 12.50 35,377 12.24 0.1055
2019-11-12 2019-09-30 13F ISHARES TR MBS ETF 464288588 291,047 36,266 14.23 31,520 14.99 0.0806
2019-08-14 2019-06-30 13F ISHARES TR MBS ETF 464288588 254,781 34,265 15.54 27,412 16.89 0.0895
2019-05-15 2019-03-31 13F ISHARES TR MBS ETF 464288588 220,516 47,451 27.42 23,451 31.11 0.0788
2019-02-13 2018-12-31 13F ISHARES TR MBS ETF 464288588 173,065 707 0.41 17,886 0.44 0.0637
2018-11-08 2018-09-30 13F ISHARES TR MBS ETF 464288588 172,358 16,610 10.66 17,808 9.75 0.0645
2018-08-03 2018-06-30 13F ISHARES TR MBS ETF 464288588 155,748 18,247 13.27 16,226 12.77 0.0551
2018-05-11 2018-03-31 13F ISHARES TR MBS ETF 464288588 137,501 28,711 26.39 14,389 24.09 0.0552
2018-02-08 2017-12-31 13F ISHARES TR MBS ETF 464288588 108,790 19,451 21.77 11,596 21.20 0.0403
2017-11-06 2017-09-30 13F ISHARES TR MBS ETF 464288588 89,339 9,792 12.31 9,568 12.66 0.0340
2017-07-31 2017-06-30 13F ISHARES TR MBS ETF 464288588 79,547 7,574 10.52 8,493 10.76 0.0339
2017-05-05 2017-03-31 13F ISHARES TR MBS ETF 464288588 71,973 11,011 18.06 7,668 18.30 0.0336
2017-02-02 2016-12-31 13F ISHARES TR MBS ETF 464288588 60,962 16,151 36.04 6,482 31.40 0.0314
2016-11-04 2016-09-30 13F ISHARES TR MBS ETF 464288588 44,811 9,750 27.81 4,933 27.93 0.0251
2016-08-11 2016-06-30 13F ISHARES TR MBS ETF 464288588 35,061 5,824 19.92 3,856 20.46 0.0231
2016-05-10 2016-03-31 13F/A-1 ISHARES TR MBS ETF 464288588 29,237 7,323 33.42 3,201 35.64 0.0199
2016-02-03 2015-12-31 13F ISHARES TR MBS ETF 464288588 21,914 9,275 73.38 2,360 70.27 0.0144
2015-11-02 2015-09-30 13F/A-1 ISHARES TR MBS ETF 464288588 12,639 757 6.37 1,386 7.36 0.0127
2015-10-30 2015-09-30 13F ISHARES TR MBS ETF 464288588 12,639 1,386
2015-08-07 2015-06-30 13F/A-1 ISHARES MBS ETF 464288588 11,882 5,814 95.81 1,291 92.69 0.0117
2015-08-04 2015-06-30 13F ISHARES MBS ETF 464288588 11,882 5,814 1,291 0.0117
2015-05-14 2015-03-31 13F/A-1 ISHARES MBS ETF 464288588 6,068 4,678 336.55 670 340.79 0.0058
2015-05-01 2015-03-31 13F IRONWOOD PHARMACEUTICALS PUT 464288588 6,068 6,068 670 0.0058
2015-02-10 2014-12-31 13F ISHARES MBS ETF 464288588 1,390 1,390 152 0.0013
Disclosed Put 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
(%)
2015-05-01 2015-03-31 13F IRONWOOD PHARMACEUTICALS PUT 6,068 670 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.