Stock Trading Canary

United States · SEC Form 4 · Snapshot date: 2026-10-18 · Built: 2026-10-18 · 中文

← United States · Coverage record

US · SEC FORM 4

Marathon Bancorp, Inc. /MD/

MBBC · Nasdaq · CIK 0001835385 · Financial Services · Banks—Regional

INSIDER SIGNAL

60.5 / 100

4 buyers · 25 purchase transaction lines · $119.7K gross purchase

WHY THIS SIGNAL?

Buyer breadthStrong
Purchase sizeLow
RoleModerate
RecencyLow
ConvictionStrong
Score anatomy

Each bar shows the contribution to the current score; the weights and formula stay unchanged.

Cluster+28.0 / 35
Purchase size+8.2 / 25
Role+13.0 / 20
Recency+1.3 / 10
Conviction+10.0 / 10

What is holding the score back?

  • ⚠ Purchase size is modest relative to the model scale
  • ⚠ Role scores low · most senior buyer: President and CEO (CEO, chair and 10% owners score lowest)
  • ⚠ Purchase activity is becoming less recent
  • ✓ Cluster breadth is broad · 4+ insiders

Purchase-size comments are relative to the model scale. Average daily volume is a separate market-context diagnostic.

US-v1.2 ranks qualifying equity purchases under the current 180-day rules. The score is a research priority, not a return forecast or probability. Backtests have not shown that a higher US score is followed by better returns.

Insider activity timeline

Owner lanes show the latest 180 days. Symbol shape identifies the transaction type; sales remain context only.

AprMayJunJulAugSepOct
Spatz NoraEVP and CAO
○○●●●●●●○○○
Zillges Nicholas WPresident and CEO
○●●●●●●○●○
Knopf MichelleEVP and COO
○●●●●●●○○
Cornish TerrySVP and CCO
○●●●●●●○○
Selting-Buchberger JoySVP and CFO
○○
Zientara AmyDirector,Other
○○
● Purchase▼ Sale○ Other

Showing the six most active owners; 3 additional owner(s) remain in Form 4 evidence.

Purchase breadth & concentration

QUALIFYING BUYERS4
PURCHASE CONCENTRATION46%Largest buyer: Spatz Nora · $54.8K
CLUSTER BUYING · 15D4 insidersPeak activity: 2026-06-03–2026-06-16

Roles in the peak window: EVP and CAO, EVP and COO, President and CEO, SVP and CCO. Concentration uses priced qualifying P lines only and does not change the saved score.

SIGNAL HISTORY

60.5 / 100

Latest recorded score

→ +0.0 ptsversus the previous recorded snapshot
  1. 60.7
  2. 60.6
  3. 60.6
  4. 60.5
  5. 60.5

Only scores saved when a full US scoring run completed are shown; gaps are not reconstructed.

Recent Form 4 activity

27Purchases
0Sales
42Other Form 4 lines
37SEC filings · 365 days
BUYING25 qualifying P line(s) · 180 days
SELLING0 sale line(s) · context only
OTHER28 exercise / withholding / award / gift / other lines
10b5-1 / PLANNEDNot assessed

P is an open-market or private purchase. S is a sale. M, F, A and G usually describe exercises, tax withholding, awards and gifts. These categories remain visually separate.

Market context

Market context provides additional background on recent price performance and risk. It does not affect the Insider Signal.

Price performance

1M
-0.3%
3M
-0.4%
6M
+13.9%
12M
+43.8%

Volatility & liquidity

Volatility
33.4%
Beta
—
Avg daily value
USD 38,648

Valuation

Market cap
USD 45.4M
P/E
25.4×

Fundamentals

Profit margin
—
ROE
3.7%
Industry
Banks—Regional

Market data

Price data up to: 2026-10-11 · Price source: OpenBB/yfinance; volume from price cache (yfinance) · From SEC filings: Market cap, P/E, ROE · Fiscal year ended: 2026-06-30 · Market cap is the shares outstanding stated on the filing cover multiplied by the latest close. Share count date: 2026-09-15 · Status: PASS

Short interest

Short interest is external context reported to FINRA by broker-dealers. It does not affect the Insider Signal.

Shares short
6,940
Previous report
6,405
Avg daily volume
4,748
Days to cover
1.5

FINRA settlement date: 2026-09-30 · Captured 2026-10-12 · FINRA equity short interest ↗. A share count, published about a week after each of two settlement dates a month; not a percentage of shares outstanding.

Historical equity purchases

Qualifying code P transactions in the local Form 4 history, including purchases outside the current signal window.

Transaction dateReporting ownerTypeSecuritySharesAvg. priceApprox. valueSource
2026-06-16Zillges Nicholas WPurchase (P)Common Stock970USD 15.00USD 14,550SEC filing ↗
2026-06-10Zillges Nicholas WPurchase (P)Common Stock170USD 14.75USD 2,508SEC filing ↗
2026-06-10Spatz NoraPurchase (P)Common Stock602USD 14.75USD 8,880SEC filing ↗
2026-06-10Knopf MichellePurchase (P)Common Stock164USD 14.75USD 2,419SEC filing ↗
2026-06-10Cornish TerryPurchase (P)Common Stock219USD 14.75USD 3,230SEC filing ↗
2026-06-09Zillges Nicholas WPurchase (P)Common Stock537USD 14.50USD 7,786SEC filing ↗
2026-06-09Spatz NoraPurchase (P)Common Stock1,904USD 14.50USD 27,608SEC filing ↗
2026-06-09Knopf MichellePurchase (P)Common Stock519USD 14.50USD 7,526SEC filing ↗
2026-06-09Cornish TerryPurchase (P)Common Stock693USD 14.50USD 10,048SEC filing ↗
2026-06-08Zillges Nicholas WPurchase (P)Common Stock55USD 14.24USD 783SEC filing ↗
2026-06-08Spatz NoraPurchase (P)Common Stock197USD 14.24USD 2,805SEC filing ↗
2026-06-08Knopf MichellePurchase (P)Common Stock54USD 14.24USD 769SEC filing ↗
2026-06-08Cornish TerryPurchase (P)Common Stock71USD 14.24USD 1,011SEC filing ↗
2026-06-05Zillges Nicholas WPurchase (P)Common Stock90USD 14.25USD 1,282SEC filing ↗
2026-06-05Spatz NoraPurchase (P)Common Stock320USD 14.25USD 4,560SEC filing ↗

Form 4 evidence

69 transaction lines in the latest 365-day window; 162 in local history.

DateOwnerTypeSecuritySharesAvg. priceApprox. valueSource
2026-09-18Spatz NoraOption exercise / conversion (M)Common Stock2,163USD 7.40USD 15,998SEC filing ↗
2026-06-28Zillges Nicholas WTax withholding (F)Common Stock1,269USD 15.49USD 19,657SEC filing ↗
2026-06-28Spatz NoraTax withholding (F)Common Stock503USD 15.49USD 7,791SEC filing ↗
Show recent Form 4 evidence (30 grouped rows)
DateOwnerTypeSecuritySharesAvg. priceApprox. valueSource
2026-09-18Spatz NoraOption exercise / conversion (M)Common Stock2,163USD 7.40USD 15,998SEC filing ↗
2026-06-28Zillges Nicholas WTax withholding (F)Common Stock1,269USD 15.49USD 19,657SEC filing ↗
2026-06-28Spatz NoraTax withholding (F)Common Stock503USD 15.49USD 7,791SEC filing ↗
2026-06-28Selting-Buchberger JoyTax withholding (F)Common Stock522USD 15.49USD 8,086SEC filing ↗
2026-06-28Knopf MichelleTax withholding (F)Common Stock225USD 15.49USD 3,485SEC filing ↗
2026-06-28Cornish TerryTax withholding (F)Common Stock247USD 15.49USD 3,826SEC filing ↗
2026-06-16Zillges Nicholas WPurchase (P)Common Stock970USD 15.00USD 14,550SEC filing ↗
2026-06-15Zillges Nicholas WAward / grant (A)Common Stock16,934USD 0.00USD 0SEC filing ↗
2026-06-15Zientara AmyAward / grant (A)Common Stock3,386USD 0.00USD 0SEC filing ↗
2026-06-15Wimmer Timothy RAward / grant (A)Common Stock3,386USD 0.00USD 0SEC filing ↗
2026-06-15Werth Ann MAward / grant (A)Common Stock3,386USD 0.00USD 0SEC filing ↗
2026-06-15Spatz NoraAward / grant (A)Common Stock6,450USD 0.00USD 0SEC filing ↗
2026-06-15Knopf MichelleAward / grant (A)Common Stock5,450USD 0.00USD 0SEC filing ↗
2026-06-15Grimm Thomas LAward / grant (A)Common Stock3,386USD 0.00USD 0SEC filing ↗
2026-06-15Cornish TerryAward / grant (A)Common Stock3,500USD 0.00USD 0SEC filing ↗
2026-06-10Zillges Nicholas WPurchase (P)Common Stock170USD 14.75USD 2,508SEC filing ↗
2026-06-10Spatz NoraPurchase (P)Common Stock602USD 14.75USD 8,880SEC filing ↗
2026-06-10Knopf MichellePurchase (P)Common Stock164USD 14.75USD 2,419SEC filing ↗
2026-06-10Cornish TerryPurchase (P)Common Stock219USD 14.75USD 3,230SEC filing ↗
2026-06-09Zillges Nicholas WPurchase (P)Common Stock537USD 14.50USD 7,786SEC filing ↗
2026-06-09Spatz NoraPurchase (P)Common Stock1,904USD 14.50USD 27,608SEC filing ↗
2026-06-09Knopf MichellePurchase (P)Common Stock519USD 14.50USD 7,526SEC filing ↗
2026-06-09Cornish TerryPurchase (P)Common Stock693USD 14.50USD 10,048SEC filing ↗
2026-06-08Zillges Nicholas WPurchase (P)Common Stock55USD 14.24USD 783SEC filing ↗
2026-06-08Spatz NoraPurchase (P)Common Stock197USD 14.24USD 2,805SEC filing ↗
2026-06-08Knopf MichellePurchase (P)Common Stock54USD 14.24USD 769SEC filing ↗
2026-06-08Cornish TerryPurchase (P)Common Stock71USD 14.24USD 1,011SEC filing ↗
2026-06-05Zillges Nicholas WPurchase (P)Common Stock90USD 14.25USD 1,282SEC filing ↗
2026-06-05Spatz NoraPurchase (P)Common Stock320USD 14.25USD 4,560SEC filing ↗
2026-06-05Knopf MichellePurchase (P)Common Stock87USD 14.25USD 1,240SEC filing ↗

Multiple price lines in one filing are grouped and share-weighted. Price and value are blank when a grouped filing line lacks price evidence.

Snapshot & identity

Snapshot date2026-10-18
Ranking versionUS-v1.2
Data qualityPASS ELIGIBLE · —
TickerMBBC
CIK0001835385
SectorFinancial Services
IndustryBanks—Regional Yahoo Finance
SEC SIC6036 Savings Institutions, Not Federally Chartered
ExchangeNasdaq

Data coverage

Local Form 4 history162 transaction lines from 2021-05-26 to 2026-09-18
38 P purchase lines · 0 S sale lines · 124 other lines
SEC company submissionsOpen SEC filings ↗

Local ledger as of 2026-10-18. Mapping status is an audit field and does not erase SEC filing evidence.