MainStreet Bancshares, Inc.
US ˙ NasdaqCM ˙ US56064Y1001

SecurityMNSB / MainStreet Bancshares, Inc.
InstitutionState Street Corp
Latest Disclosed Ownership100,211 shares
Latest Disclosed Value $ 2,224,684
State Street Corp reports 36.23% increase in ownership of MNSB / MainStreet Bancshares, Inc.

On May 15, 2026 - State Street Corp filed a 13F-HR form disclosing ownership of 100,211 shares of MainStreet Bancshares, Inc. (US:MNSB) valued at $2,224,684 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 13, 2026 disclosing 73,562 shares of MainStreet Bancshares, Inc.. This represents a change in shares of 36.23% during the quarter. The current value of the position is $2,335,918 USD.

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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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)
2026-05-15 2026-03-31 13F MAINSTREET BANCSHARES COM 56064Y100 100,211 26,649 36.23 2,225 48.56 0.0001
2026-02-13 2025-12-31 13F MAINSTREET BANCSHARES COM 56064Y100 73,562 582 0.80 1,498 -1.51 0.0001
2025-11-14 2025-09-30 13F MAINSTREET BANCSHARES COM 56064Y100 72,980 5,795 8.63 1,520 19.78 0.0001
2025-08-14 2025-06-30 13F MAINSTREET BANCSHARES COM 56064Y100 67,185 44,940 202.02 1,270 242.05 0.0000
2025-05-15 2025-03-31 13F MAINSTREET BANCSHARES COM 56064Y100 22,245 0 0.00 372 -7.71 0.0000
2025-02-14 2024-12-31 13F MAINSTREET BANCSHARES COM 56064Y100 22,245 1,018 4.80 403 2.81 0.0000
2024-11-14 2024-09-30 13F MAINSTREET BANCSHARES COM 56064Y100 21,227 0 0.00 392 3.99 0.0000
2024-08-14 2024-06-30 13F MAINSTREET BANCSHARES COM 56064Y100 21,227 -56,613 -72.73 376 -73.39 0.0000
2024-05-15 2024-03-31 13F MAINSTREET BANCSHARES COM 56064Y100 77,840 1,700 2.23 1,414 -25.20 0.0001
2024-02-14 2023-12-31 13F MAINSTREET BANCSHARES COM 56064Y100 76,140 122 0.16 1,889 21.01 0.0001
2023-11-14 2023-09-30 13F MAINSTREET BANCSHARES COM 56064Y100 76,018 1,068 1.42 1,561 -8.07 0.0001
2023-08-14 2023-06-30 13F MAINSTREET BANCSHARES COM 56064Y100 74,950 52,823 238.73 1,698 227.17 0.0001
2023-05-15 2023-03-31 13F MAINSTREET BANCSHARES COM 56064Y100 22,127 0 0.00 520 -14.64 0.0000
2023-05-15 2022-12-31 13F/A-99 MAINSTREET BANCSHARES COM 56064Y100 22,127 -740 -3.24 608 16.48 0.0000
2023-05-15 2022-12-31 13F MAINSTREET BANCSHARES COM 56064Y100 22,127 -740 608 0.0000
2022-11-15 2022-09-30 13F MAINSTREET BANCSHARES COM 56064Y100 22,867 4,086 21.76 522 21.96 0.0000
2022-08-15 2022-06-30 13F MAINSTREET BANCSHARES COM 56064Y100 18,781 0 0.00 428 -6.35 0.0000
2022-05-16 2022-03-31 13F MAINSTREET BANCSHARES COM 56064Y100 18,781 1,554 9.02 457 7.78 0.0000
2022-02-14 2021-12-31 13F MAINSTREET BANCSHARES COM 56064Y100 17,227 0 0.00 424 2.66 0.0000
2021-11-15 2021-09-30 13F MAINSTREET BANCSHARES COM 56064Y100 17,227 3,700 27.35 413 35.41 0.0000
2021-08-16 2021-06-30 13F MAINSTREET BANCSHARES COM 56064Y100 13,527 -93,780 -87.39 305 -86.31 0.0000
2021-07-09 2021-03-31 13F/A-1 MAINSTREET BANCSHARES COM 56064Y100 107,307 -10,600 -8.99 2,228 11.74 0.0001
2021-05-17 2021-03-31 13F MAINSTREET BANCSHARES COM 56064Y100 107,307 -10,600 2,228 0.0001
2021-02-16 2020-12-31 13F MAINSTREET BANCSHARES COM 56064Y100 117,907 -4,346 -3.55 1,994 33.29 0.0001
2020-11-10 2020-09-30 13F MAINSTREET BANCSHARES COM 56064Y100 122,253 -700 -0.57 1,496 -7.83 0.0001
2020-08-14 2020-06-30 13F MAINSTREET BANCSHARES COM 56064Y100 122,953 8,258 7.20 1,623 -15.56 0.0001
2020-06-19 2020-03-31 13F/A-1 MAINSTREET BANCSHARES COM 56064Y100 114,695 31,023 37.08 1,922 -0.10 0.0002
2020-05-11 2020-03-31 13F MAINSTREET BANCSHARES COM 56064Y100 114,695 31,023 1,922 168.7903
2020-02-06 2019-12-31 13F MAINSTREET BANCSHARES COM 56064Y100 83,672 -2,562 -2.97 1,924 6.01 0.0001
2019-11-14 2019-09-30 13F MAINSTREET BANCSHARES COM 56064Y100 86,234 12,735 17.33 1,815 102.12 0.0001
2019-08-14 2019-06-30 13F MAINSTREET BANCSHARES COM 56064Y100 73,499 73,499 898 0.0001
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.