MPWR EVP sells 12,000 shares under trading plan
Monolithic Power Systems executive Maurice Sciammas, EVP of Worldwide Sales & Marketing, reported open-market sales of 12,000 shares of common stock on May 15, 2026.
Rhea-AI Filing Summary
Monolithic Power Systems executive Maurice Sciammas, EVP of Worldwide Sales & Marketing, reported open-market sales of 12,000 shares of common stock on May 15, 2026. The shares were sold in multiple transactions at prices generally ranging from about $1,550 to $1,586 per share.
The filing states these sales were made under a Rule 10b5-1 trading plan adopted on November 24, 2025, indicating they were pre-arranged. Following the transactions, Sciammas directly holds 166,644 shares of Monolithic Power Systems common stock, in addition to various indirect holdings through family trusts and related accounts.
Positive
- None.
Negative
- None.
Insider Trade Summary 10b5-1
Net Seller: 12,000 shares
Net Sell
19 txns
Insider
Sciammas Maurice
Role
EVP, WW Sales & Marketing
Sold
12,000 shs ($18.74M)
| Type | Security | Shares | Price | Value |
|---|---|---|---|---|
| Sale | Common Stock | 3,741 | $1,550.36 | $5.80M |
| Sale | Common Stock | 1,717 | $1,557.48 | $2.67M |
| Sale | Common Stock | 2,010 | $1,562.01 | $3.14M |
| Sale | Common Stock | 2,020 | $1,567.15 | $3.17M |
| Sale | Common Stock | 1,312 | $1,571.49 | $2.06M |
| Sale | Common Stock | 703 | $1,577.75 | $1.11M |
| Sale | Common Stock | 447 | $1,582.21 | $707K |
| Sale | Common Stock | 50 | $1,585.51 | $79K |
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Holdings After Transaction:
Common Stock — 166,644 shares (Direct);
Common Stock — 1,699 shares (Indirect, The Joseph Roger Sciammas 2020 Irrevocable Trust);
Common Stock — 2,000 shares (Indirect, Rosalind Sciammas Family 2021 Trust);
Common Stock — 51,023 shares (Indirect, Sciammas Family Trust);
Common Stock — 25,097 shares (Indirect, Various Sciammas GRATs);
Common Stock — 1,699 shares (Indirect, The Patrick Francis Sciammas 2020 Irrevocable Trust);
Common Stock — 4,015 shares (Indirect, By Sciammas Trust 2020);
Common Stock — 1,000 shares (Indirect, Peter Rafferty and Eric Toothill 2021Trust);
Common Stock — 1,699 shares (Indirect, The Chloe Liliane Sciammas 2020 Irrevocable Trust);
Common Stock — 1,209 shares (Indirect, Clement Sciammas Trust);
Common Stock — 5,000 shares (Indirect, Clement Sciammas Family 2021 Trust);
Common Stock — 919 shares (Indirect, Rosalind Sciammas Brokerage Account)
Footnotes (9)
- F1. This transaction was made pursuant to a Rule 10b5-1 trading plan adopted on 11/24/2025.
- F2. The price is the weighted average sale price for the transactions reported on this line. The prices for the transactions reported on this line range from $1,549.62 to $1,554.55. The reporting person undertakes to provide, upon request by the staff of the Securities and Exchange Commission, the issuer, or a security holder of the issuer, full information regarding the number of shares sold at each separate price.
- F3. The price is the weighted average sale price for the transactions reported on this line. The prices for the transactions reported on this line range from $1,554.59 to $1,559.37. The reporting person undertakes to provide, upon request by the staff of the Securities and Exchange Commission, the issuer, or a security holder of the issuer, full information regarding the number of shares sold at each separate price.
- F4. The price is the weighted average sale price for the transactions reported on this line. The prices for the transactions reported on this line range from $1,559.61 to $1,564.59. The reporting person undertakes to provide, upon request by the staff of the Securities and Exchange Commission, the issuer, or a security holder of the issuer, full information regarding the number of shares sold at each separate price.
- F5. The price is the weighted average sale price for the transactions reported on this line. The prices for the transactions reported on this line range from $1,564.75 to $1,569.67. The reporting person undertakes to provide, upon request by the staff of the Securities and Exchange Commission, the issuer, or a security holder of the issuer, full information regarding the number of shares sold at each separate price.
- F6. The price is the weighted average sale price for the transactions reported on this line. The prices for the transactions reported on this line range from $1,569.78 to $1,574.53. The reporting person undertakes to provide, upon request by the staff of the Securities and Exchange Commission, the issuer, or a security holder of the issuer, full information regarding the number of shares sold at each separate price.
- F7. The price is the weighted average sale price for the transactions reported on this line. The prices for the transactions reported on this line range from $1,574.9 to $1,579.7. The reporting person undertakes to provide, upon request by the staff of the Securities and Exchange Commission, the issuer, or a security holder of the issuer, full information regarding the number of shares sold at each separate price.
- F8. The price is the weighted average sale price for the transactions reported on this line. The prices for the transactions reported on this line range from $1,579.97 to $1,584.43. The reporting person undertakes to provide, upon request by the staff of the Securities and Exchange Commission, the issuer, or a security holder of the issuer, full information regarding the number of shares sold at each separate price.
- F9. The price is the weighted average sale price for the transactions reported on this line. The prices for the transactions reported on this line range from $1,585.17 to $1,586.76. The reporting person undertakes to provide, upon request by the staff of the Securities and Exchange Commission, the issuer, or a security holder of the issuer, full information regarding the number of shares sold at each separate price.
Key Figures
Shares sold: 12,000 shares
Sale price example: $1,550.36 per share
Highest price range: $1,585.17–$1,586.76
+5 more
8 metrics
Shares sold
12,000 shares
Total common stock sold on May 15, 2026
Sale price example
$1,550.36 per share
One of several reported open-market sale prices
Highest price range
$1,585.17–$1,586.76
Weighted average price range noted in a footnote
Lowest price range
$1,549.62–$1,554.55
Weighted average price range noted in a footnote
Direct holdings after sale
174,903 shares
Direct MPWR common stock owned following the transactions
Sciammas Family Trust holdings
51,023 shares
Indirect MPWR holdings via Sciammas Family Trust
Various Sciammas GRATs holdings
25,097 shares
Indirect MPWR holdings via various GRATs
10b5-1 plan adoption date
November 24, 2025
Date the trading plan governing these sales was adopted
Key Terms
Rule 10b5-1 trading plan, weighted average sale price, irrevocable trust, GRATs, +1 more
5 terms
Rule 10b5-1 trading plan regulatory
"This transaction was made pursuant to a Rule 10b5-1 trading plan adopted on 11/24/2025."
A Rule 10b5-1 trading plan is a pre-arranged schedule that allows company insiders to buy or sell stock at specific times, even if they have inside information. It helps prevent accusations of unfair trading by making these transactions look planned and transparent, rather than sneaky or illegal.
weighted average sale price financial
"The price is the weighted average sale price for the transactions reported on this line."
irrevocable trust financial
"The Chloe Liliane Sciammas 2020 Irrevocable Trust"
An irrevocable trust is a legal arrangement where an owner transfers assets into a separate entity managed by a trustee and gives up the power to modify or reclaim those assets. For investors it matters because putting stock or other holdings into such a trust can change who controls and benefits from the assets, affect taxes and creditor protection, and influence how easy it is to sell or value those holdings—like placing valuables in a locked safe overseen by someone else.
GRATs financial
"Various Sciammas GRATs"
open-market sale market
"Sale in open market or private transaction"
An open-market sale is when a shareholder sells existing shares directly on a public exchange to any willing buyer, rather than through a private deal. Think of it like putting goods on a busy market stall where price is set by supply and demand; for investors it matters because such sales increase available supply, can put short-term downward pressure on the stock price, and signal changes in liquidity or investor confidence.
FAQ
AI-generated questions and answers. How Rhea-AI works. Not financial advice.
What insider activity did MPWR executive Maurice Sciammas report on this Form 4?
Maurice Sciammas reported selling 12,000 shares of Monolithic Power Systems common stock in open-market transactions on May 15, 2026. These trades were executed across multiple price points generally between about $1,550 and $1,586 per share, according to the filing details.
Were Maurice Sciammas’ MPWR stock sales made under a Rule 10b5-1 plan?
Yes. A footnote states the 12,000-share sale was made under a Rule 10b5-1 trading plan adopted on November 24, 2025. Such plans pre-schedule trades, so the timing reflects the plan’s terms rather than day-to-day market decisions.
AI-generated analysis. How Rhea-AI works. Not financial advice.
