SCHEDULE: Castle Creek Reduces Middlefield Banc Stake to 3.9%

Castle Creek Capital Partners VI, LP has significantly reduced its stake in Middlefield Banc Corp., selling 247,653 shares and dropping below the 5% beneficial ownership threshold.

Summary

• Castle Creek Capital Partners VI, LP (Fund VI) sold a total of 247,653 shares of Middlefield Banc Corp. common stock.
• The sales occurred between December 12, 2025, and February 2, 2026, generating net proceeds of $8,546,310.15.
• Following these transactions, Fund VI now owns 312,847 shares, representing approximately 3.9% of Middlefield Banc Corp.'s outstanding voting common stock.
• The calculation of ownership percentage is based on 8,090,067 shares outstanding as of December 12, 2025.
• As of February 2, 2026, the reporting persons (Castle Creek Capital Partners VI, LP and Castle Creek Capital VI LLC) ceased to be beneficial owners of more than five percent of the voting common stock.

Sentiment

Score: 3

Explanation: StockSavvy.ai views this as a moderately negative development for Middlefield Banc Corp. given the significant reduction in a major institutional investor's stake and the declining share price during the divestment period.

Negatives

• A significant institutional investor, Castle Creek Capital Partners VI, LP, has reduced its stake in Middlefield Banc Corp. by 247,653 shares.
• The reporting persons are no longer beneficial owners of more than 5% of the company's voting common stock, which could be perceived negatively by some investors.
• The average sale prices for shares on January 30, 2026 ($33.57) and February 2, 2026 ($33.61) were notably lower than earlier sales in December 2025 (e.g., $37.17 on December 12, 2025), indicating a decline in share price during the selling period.

Future Outlook

The filing does not contain any forward-looking statements or guidance regarding Middlefield Banc Corp.'s future performance or strategic direction.

Industry Context

StockSavvy.ai notes that a reduction in a significant institutional stake, particularly below the 5% threshold, can sometimes signal a shift in an investor's strategy or outlook on the company or the broader regional banking sector. While not explicitly stated, such a move might reflect a decision to reallocate capital or a less optimistic view on the company's near-term prospects compared to other opportunities, or simply a portfolio rebalancing.

Stakeholder Impact

• Shareholders: Existing shareholders might view the reduction in a significant institutional stake as a negative signal, potentially leading to downward pressure on the stock price. The sale of a large block of shares could also increase market supply.
• Company Management: Management may need to address investor concerns regarding the institutional divestment and articulate their strategy to maintain investor confidence.

Key Dates

Recommendation

While a significant institutional investor has reduced its stake, the filing itself does not provide fundamental information about Middlefield Banc Corp.'s operations or financial health to warrant a strong buy or sell recommendation. The reduction in ownership by Castle Creek Capital is a notable event, but without further context on the company's performance or strategic outlook, a 'hold' recommendation is appropriate for investors to assess the broader implications and wait for more comprehensive financial reporting.

Keywords

Middlefield Banc Corp, Castle Creek Capital, Schedule 13D/A, share sale, institutional ownership, bank stock, financial services, equity stake, beneficial ownership