MainStreet Bancshares, Inc.
US ˙ NasdaqCM ˙ US56064Y1001

SecurityMNSB / MainStreet Bancshares, Inc.
InstitutionAlliancebernstein L.p.
Latest Disclosed Ownership554,723 shares
Ownership 7.50%
Alliancebernstein L.p. ownership in MNSB / MainStreet Bancshares, Inc.

2026-05-18 - Alliancebernstein L.p. has filed an SCHEDULE 13G/A form with the Securities and Exchange Commission (SEC) disclosing ownership of 554,723 shares of MainStreet Bancshares, Inc. (US:MNSB). This represents 7.5 percent ownership of the company. In their previous filing dated 2024-11-15 , Alliancebernstein L.p. had reported owning 648,797 shares, indicating a decrease of -14.50 percent.

Institutional Ownership: 13D/G Filings

This table shows a history of the 13D/G filings made by the investor and/or investor group. Note that the share values in this table are not directly comparable to any numbers shown in the 13F table (if any).

File
Date
Effective
Date
Form Prev
Shares
Latest
Shares
ΔShares
(Percent)
Ownership
(Percent)
ΔOwnership
(Percent)
2026-05-18 2026-05-18 13G/A 648,797 554,723 -14.50 7.50 -11.76
2024-11-15 2024-11-15 13G/A 560,196 648,797 15.82 8.50 14.86
2024-02-14 2024-02-14 13G/A 405,478 560,196 38.16 7.40 34.55
2023-02-14 2023-02-14 13G 405,478 405,478 0.00 5.50 0.00

Important Note: One of the primary uses of the 13D/G filings is to evaluate the ability of a firm to control a company (ie, the "beneficial ownership"). To that end, firms are required to report not just direct holdings in companies, but indirect holdings that they control. For investment firms, these indirect holdings can include shares in funds they manage, advisory accounts, and in the case of activist campaigns, pledged votes. Therefore, share counts listed in 13D/G filings can differ significantly than share counts listed in 13F filings.

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 554,723 -130,222 -19.01 11,294 -19.01 0.0031
2026-02-17 2025-12-31 13F MAINSTREET BANCSHARES COM 56064Y100 684,945 10,782 1.60 13,945 -0.69 0.0044
2025-11-14 2025-09-30 13F MAINSTREET BANCSHARES COM 56064Y100 674,163 17,515 2.67 14,043 13.15 0.0044
2025-08-14 2025-06-30 13F MAINSTREET BANCSHARES COM 56064Y100 656,648 5,851 0.90 12,411 14.05 0.0040
2025-05-15 2025-03-31 13F MAINSTREET BANCSHARES COM 56064Y100 650,797 2,000 0.31 10,881 -7.34 0.0039
2025-02-12 2024-12-31 13F MAINSTREET BANCSHARES COM 56064Y100 648,797 0 0.00 11,743 -1.90 0.0040
2024-11-14 2024-09-30 13F MAINSTREET BANCSHARES COM 56064Y100 648,797 11,297 1.77 11,970 5.91 0.0040
2024-08-14 2024-06-30 13F MAINSTREET BANCSHARES COM 56064Y100 637,500 54,884 9.42 11,303 6.82 0.0039
2024-05-14 2024-03-31 13F MAINSTREET BANCSHARES COM 56064Y100 582,616 22,420 4.00 10,580 -23.87 0.0037
2024-02-14 2023-12-31 13F MAINSTREET BANCSHARES COM 56064Y100 560,196 8,854 1.61 13,898 22.73 0.0053
2023-11-14 2023-09-30 13F MAINSTREET BANCSHARES COM 56064Y100 551,342 39,472 7.71 11,325 -2.36 0.0048
2023-08-15 2023-06-30 13F MAINSTREET BANCSHARES COM 56064Y100 511,870 66,169 14.85 11,599 10.78 0.0047
2023-05-15 2023-03-31 13F MAINSTREET BANCSHARES COM 56064Y100 445,701 40,223 9.92 10,470 -6.07 0.0045
2023-02-15 2022-12-31 13F MAINSTREET BANCSHARES COM 56064Y100 405,478 8,292 2.09 11,147 23.02 0.0050
2022-11-15 2022-09-30 13F MAINSTREET BANCSHARES COM 56064Y100 397,186 50,424 14.54 9,060 14.74 0.0044
2022-08-15 2022-06-30 13F MAINSTREET BANCSHARES COM 56064Y100 346,762 33,030 10.53 7,896 3.53 0.0036
2022-05-13 2022-03-31 13F MAINSTREET BANCSHARES COM 56064Y100 313,732 8,178 2.68 7,627 1.50 0.0029
2022-02-14 2021-12-31 13F MAINSTREET BANCSHARES COM 56064Y100 305,554 16,514 5.71 7,514 8.36 0.0027
2021-11-10 2021-09-30 13F MAINSTREET BANCSHARES COM 56064Y100 289,040 100,517 53.32 6,934 62.88 0.0027
2021-07-30 2021-06-30 13F MAINSTREET BANCSHARES COM 56064Y100 188,523 10,861 6.11 4,257 15.43 0.0017
2021-05-06 2021-03-31 13F MAINSTREET BANCSHARES COM 56064Y100 177,662 -1,000 -0.56 3,688 22.08 0.0016
2021-02-08 2020-12-31 13F MAINSTREET BANCSHARES COM 56064Y100 178,662 -25,200 -12.36 3,021 21.08 0.0014
2020-11-12 2020-09-30 13F MAINSTREET BANCSHARES COM 56064Y100 203,862 16,378 8.74 2,495 0.81 0.0013
2020-08-13 2020-06-30 13F MAINSTREET BANCSHARES COM 56064Y100 187,484 36,400 24.09 2,475 -2.25 0.0015
2020-05-14 2020-03-31 13F MAINSTREET BANCSHARES COM 56064Y100 151,084 21,689 16.76 2,532 -14.92 0.0018
2020-02-18 2019-12-31 13F MAINSTREET BANCSHARES COM 56064Y100 129,395 129,395 2,976 0.0017
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.