Form 4: Monolithic Power CFO Sells Shares Under 10b5-1 Plan

Monolithic Power Systems' EVP and CFO, Theodore Blegen, sold 3,040 shares of common stock for approximately $2.72 million on December 1, 2025, pursuant to a pre-arranged 10b5-1 trading plan.

Summary

• Theodore Blegen, Executive Vice President and Chief Financial Officer of Monolithic Power Systems Inc. (MPWR), reported the sale of common stock.
• A total of 3,040 shares of common stock were disposed of on December 1, 2025.
• The sales were executed at prices ranging from $899.73 to $911.59 per share, with weighted average prices reported for certain transactions.
• The total value of the shares sold is approximately $2,724,723.44.
• These transactions were conducted pursuant to a Rule 10b5-1 trading plan, which was adopted by Mr. Blegen on February 26, 2025.
• Following these transactions, Mr. Blegen directly beneficially owns 71,332 shares of common stock.
• Additionally, Mr. Blegen indirectly beneficially owns 5,331 shares through an Irrevocable Trust FBO Sarah N. Blegen and 5,331 shares through an Irrevocable Trust FBO Theodore F. Blegen.

Sentiment

Score: 5

Explanation: The sale of shares by a key executive is generally neutral when conducted under a pre-arranged 10b5-1 plan, indicating a planned liquidity event rather than a reaction to new information. It does not inherently signal a positive or negative outlook for the company.

Positives

• The transactions were executed under a pre-arranged Rule 10b5-1 trading plan, indicating a planned liquidity event rather than a reaction to new, non-public information, which enhances transparency.

Negatives

• Insider selling, even under a 10b5-1 plan, can sometimes be perceived by the market as a lack of confidence, although this is mitigated by the pre-scheduled nature of the sales.

Future Outlook

This filing, an insider transaction report, does not contain any forward-looking statements or guidance regarding the company's future performance or outlook.

Industry Context

This insider transaction report does not provide specific industry context or relate to broader industry trends, focusing solely on the executive's personal stock transactions.

Corporate Governance

Related Party Transactions

• The reporting person indirectly holds shares through two irrevocable trusts established for the benefit of Sarah N. Blegen and Theodore F. Blegen, which are considered related parties.

Stakeholder Impact

• Shareholders: The sale represents a minor reduction in insider ownership, which is generally neutral given the pre-planned nature of the transaction under a 10b5-1 plan. It does not suggest a change in the company's fundamental value.

Key Dates

Recommendation

This Form 4 filing reports routine insider selling under a pre-established 10b5-1 plan and does not provide new information that would alter the fundamental investment thesis for Monolithic Power Systems. Investors should maintain their current position based on broader company performance and market conditions, as this transaction is not indicative of a change in company prospects.

Keywords

Monolithic Power Systems, MPWR, Insider Trading, Form 4, Stock Sale, Theodore Blegen, CFO, 10b5-1 Plan, Semiconductor