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Marathon Bancorp

MBBC on Nasdaq. Market value $45m.

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Should I look at this?

We have not checked this company yet

This is not advice.

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Who owns it

1 long-term investor we follow owns it, unchanged from 1 last quarter. 12 funds in all.

Jun '25
Dec '25
Jun '26
Largest holders overall

From 13F filings for the quarter ended 30 June 2026.

Big holders and activists

3 investors own more than 5%.

  • Marathon Bank Employee Stock Ownership Plan Trust
    Passive investor
    8.7%
    Since 30 June 2025
  • Marathon Bank 401(k) Plan Trust
    Passive investor
    7.3%+0.8 pts
    Since 30 June 2026
  • AllianceBernstein L.P.
    Passive investor
    5.2%
    Since 31 December 2025

From Schedule 13D and 13G filings: anyone owning more than 5% must file one.

What insiders did

In the last 12 months, 4 insiders bought $146,455 of shares on the open market.

  • Zillges Nicholas W
    President and CEO, Director
    Bought
    Date
    16 June 2026
    Shares
    970
    Price
    $15.00
    Value
    $14,550
  • Cornish Terry
    SVP and CCO
    Bought
    Date
    10 June 2026
    Shares
    219
    Price
    $14.75
    Value
    $3,230
  • Knopf Michelle
    EVP and COO
    Bought
    Date
    10 June 2026
    Shares
    164
    Price
    $14.75
    Value
    $2,419
  • Zillges Nicholas W
    President and CEO, Director
    Bought
    Date
    10 June 2026
    Shares
    170
    Price
    $14.75
    Value
    $2,508
  • Spatz Nora
    EVP and CAO
    Bought
    Date
    10 June 2026
    Shares
    602
    Price
    $14.75
    Value
    $8,880
  • Cornish Terry
    SVP and CCO
    Bought
    Date
    9 June 2026
    Shares
    693
    Price
    $14.50
    Value
    $10,049
  • Knopf Michelle
    EVP and COO
    Bought
    Date
    9 June 2026
    Shares
    519
    Price
    $14.50
    Value
    $7,526
  • Zillges Nicholas W
    President and CEO, Director
    Bought
    Date
    9 June 2026
    Shares
    537
    Price
    $14.50
    Value
    $7,787
  • Spatz Nora
    EVP and CAO
    Bought
    Date
    9 June 2026
    Shares
    1,904
    Price
    $14.50
    Value
    $27,608
  • Cornish Terry
    SVP and CCO
    Bought
    Date
    8 June 2026
    Shares
    71
    Price
    $14.24
    Value
    $1,011

From Form 4 filings: insiders must report trades in their own company's shares within two days.

Warning signs in its filings

Problems the company itself reported to the SEC, in its own words.

None of the warning signs we check for were found.

We look for five warning signs: doubt it can keep going, weak checks on its own accounts, a notice that its past accounts can't be relied on, a change of auditor, and one customer bringing in a big share of sales. We don't check lawsuits, investigations or debt yet.

We checked the auditor's report, internal controls, restatement notices, auditor changes and big customers in the 10-K filed 16 Sep 2026, plus 1 later 8-K.

A 10-K is the yearly report every US company files with the SEC. An 8-K is a short notice of a big event.

The deep dive

Everything above is arithmetic on public filings. The deep dive reads the last ten years of annual reports, the proxy statements, and the earnings calls, then argues the case the way Buffett, Klarman, and Hohn would, and checks every claim against the source.

  • What the business is worth, as a range, and the margin of safety at today’s price
  • Prices to start buying, buy, and buy hard
  • The three things that would make this a mistake
  • Every number footnoted to the filing it came from
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What a finished deep dive looks like

Not advice. Numbers on this page come from SEC filings and are updated each night; prices are updated again after the US market closes. The five-year figures are rounded.