MARATHON BANCORP INC MBBC
COM NEW · Common Stock · CUSIP 565759206
- SectorFinancials
- IndustrySavings Institutions, Not Federally Chartered
- HeadquartersWausau, WI
- FilingsSEC EDGAR
* Summed across managers. Shares that two managers' reports both contain – a subsidiary's holdings that its parent's report includes too, or a sub-adviser's in its client's – are counted once. Holder counts are more reliable. Shares outstanding: 3.0m as of 2026-05-12, from the company's own SEC filing; the percentage can still exceed 100%: lent-out shares are counted by the lender and the buyer, and some reports overlap without saying so. Implied quarter-end price ≈ $14.92.
Trends to Q2 2026
Institutional holders
Managers reporting a position, each quarter
Numbers
| Quarter | Holders |
|---|---|
| Q2 2025 | 12 |
| Q3 2025 | 10 |
| Q4 2025 | 9 |
| Q1 2026 | 9 |
| Q2 2026 | 12 |
Buyers vs sellers
Managers adding to or starting a position, vs cutting or selling out
Numbers
| Quarter | Bought or added | Cut or sold out |
|---|---|---|
| Q3 2025 | 5 | 4 |
| Q4 2025 | 5 | 3 |
| Q1 2026 | 0 | 2 |
| Q2 2026 | 6 | 4 |
Biggest buyers
| RAFFLES ASSOCIATES LP | Added | +107.7k |
| CITADEL ADVISORS LLC | New | +11.0k |
| GEODE CAPITAL MANAGEMENT, LLC | New | +10.9k |
| BlackRock, Inc. | New | +8.4k |
| MALTESE CAPITAL MANAGEMENT LLC | Added | +198 |
| UBS Group AG | New | +89 |
Biggest sellers
| VANGUARD FIDUCIARY TRUST CO | Reduced | -4.9k |
| Minerva Advisors LLC | Reduced | -3.2k |
| VANGUARD CAPITAL MANAGEMENT LLC | Reduced | -571 |
| Tower Research Capital LLC (TRC) | Sold out | -226 |
Major shareholders (over 5%)
Anyone who owns more than 5% of a class of the company's shares has to say so: on Schedule 13D if they may try to influence or control the company, on 13G if they're a passive investor, and update it as the stake changes. Each holder's latest filing, from 19 Dec 2024 on; percentages are of the share class, as the holder worked them out.
| Holder | Stake |
|---|---|
| Marathon Bank Employee Stock Ownership Plan Trust 13G · institution new · filed 2025-09-02 | 8.7% |
| Marathon Bank 401(k) Plan Trust 13G · institution +0.8 pts · filed 2026-07-01 | 7.3% |
| ALLIANCEBERNSTEIN L.P. 13G · institution new · filed 2026-02-17 | 5.2% |
Insider purchases and sales since 1 Apr 2026
Shares bought or sold by the company's own officers, directors and 10% owners, in the open market or privately, as they reported to the SEC on Form 4 (due within two business days of the trade). Grants, option exercises, shares withheld for tax and gifts aren't included.
Officers and directors buying vs selling
Number of people, by quarter (10% owners not included)
Numbers
| Quarter | Buying | Bought | Selling | Sold | Sold under a plan |
|---|---|---|---|---|---|
| Q4 2024 | 0 | — | 0 | — | — |
| Q1 2025 | 0 | — | 0 | — | — |
| Q2 2025 | 1 | $10.0k | 0 | — | — |
| Q3 2025 | 0 | — | 0 | — | — |
| Q4 2025 | 1 | $26.8k | 0 | — | — |
| Q1 2026 | 0 | — | 0 | — | — |
| Q2 2026 | 4 | $119.7k | 0 | — | — |
| Q3 2026 | 0 | — | 0 | — | — |
| Date | Insider | Trade | Value |
|---|---|---|---|
| 2026-06-16 | Zillges Nicholas W President and CEO, director | Bought | $14.6k970 shares |
| 2026-06-10 | Spatz Nora EVP and CAO · By 401(k) | Bought | $8.9k602 shares |
| 2026-06-10 | Cornish Terry SVP and CCO · By 401(k) | Bought | $3.2k219 shares |
| 2026-06-10 | Zillges Nicholas W President and CEO, director · By 401(k) | Bought | $2.5k170 shares |
| 2026-06-10 | Knopf Michelle EVP and COO · By 401(k) | Bought | $2.4k164 shares |
| 2026-06-09 | Spatz Nora EVP and CAO · By 401(k) | Bought | $27.6k1.9k shares |
| 2026-06-09 | Cornish Terry SVP and CCO · By 401(k) | Bought | $10.0k693 shares |
| 2026-06-09 | Zillges Nicholas W President and CEO, director · By 401(k) | Bought | $7.8k537 shares |
| 2026-06-09 | Knopf Michelle EVP and COO · By 401(k) | Bought | $7.5k519 shares |
| 2026-06-08 | Spatz Nora EVP and CAO · By 401(k) | Bought | $2.8k197 shares |
| 2026-06-08 | Cornish Terry SVP and CCO · By 401(k) | Bought | $1.0k71 shares |
| 2026-06-08 | Zillges Nicholas W President and CEO, director · By 401(k) | Bought | $78355 shares |
| 2026-06-08 | Knopf Michelle EVP and COO · By 401(k) | Bought | $76954 shares |
| 2026-06-05 | Spatz Nora EVP and CAO · By 401(k) | Bought | $4.6k320 shares |
| 2026-06-05 | Cornish Terry SVP and CCO · By 401(k) | Bought | $1.7k116 shares |
| 2026-06-05 | Zillges Nicholas W President and CEO, director · By 401(k) | Bought | $1.3k90 shares |
| 2026-06-05 | Knopf Michelle EVP and COO · By 401(k) | Bought | $1.2k87 shares |
| 2026-06-04 | Spatz Nora EVP and CAO · By 401(k) | Bought | $1.0k74 shares |
| 2026-06-04 | Cornish Terry SVP and CCO · By 401(k) | Bought | $37227 shares |
| 2026-06-04 | Zillges Nicholas W President and CEO, director · By 401(k) | Bought | $28921 shares |
| 2026-06-04 | Knopf Michelle EVP and COO · By 401(k) | Bought | $27520 shares |
| 2026-06-03 | Spatz Nora EVP and CAO · By 401(k) | Bought | $9.9k722 shares |
| 2026-06-03 | Cornish Terry SVP and CCO · By 401(k) | Bought | $3.6k263 shares |
| 2026-06-03 | Zillges Nicholas W President and CEO, director · By 401(k) | Bought | $2.8k203 shares |
| 2026-06-03 | Knopf Michelle EVP and COO · By 401(k) | Bought | $2.7k197 shares |
Their holding: how much the trade added to or took from the insider's holding (direct, or the trust or fund named). The same trade is sometimes reported by more than one insider, such as a fund and the director who represents it; totals count it once. A value is left blank where the reported price is far from the market price (usually a typo).
Holders, Q2 2026
| Manager | Shares | Change |
|---|---|---|
| RAFFLES ASSOCIATES LP 1.44% of their portfolio | 215.3k $3.3m | Added +107.7k |
| ALLIANCEBERNSTEIN L.P. 0.00% of their portfolio | 153.2k $2.1m | Unchanged |
| MALTESE CAPITAL MANAGEMENT LLC 0.40% of their portfolio | 145.3k $2.2m | Added +198 |
| VANGUARD CAPITAL MANAGEMENT LLC 0.00% of their portfolio | 76.0k $1.2m | Reduced -571 |
| Minerva Advisors LLC 0.54% of their portfolio | 55.8k $851.9k | Reduced -3.2k |
| KLCM Advisors, Inc. 0.04% of their portfolio | 34.3k $524.4k | Unchanged |
| STILWELL VALUE LLC 0.18% of their portfolio | 20.0k $305.6k | Unchanged |
| VANGUARD FIDUCIARY TRUST CO 0.00% of their portfolio | 11.5k $175.9k | Reduced -4.9k |
| CITADEL ADVISORS LLC 0.00% of their portfolio | 11.0k $167.8k | New |
| GEODE CAPITAL MANAGEMENT, LLC 0.00% of their portfolio | 10.9k $166.1k | New |
| BlackRock, Inc. 0.00% of their portfolio | 8.4k $127.7k | New |
| UBS Group AG 0.00% of their portfolio | 89 $1.4k | New |