Monolithic Power (MPWR) CEO sells 40,000 shares, retains large stake
Filing Impact
Filing Sentiment
Form Type
4
Rhea-AI Filing Summary
Monolithic Power Systems CEO Michael Hsing sold 40,000 shares of common stock in open-market transactions. The Form 4 shows 13 separate sales on May 18, 2026, with reported prices including $1,467.62, $1,486.76 and $1,521.43 per share.
After these sales, Hsing directly holds 879,020 shares. He also has indirect holdings of 12,825 shares through the ZH Family 2020 Trust and 133,040 shares through the M Hsing 04 Trust. A footnote notes that the ending balance includes 29 shares acquired through the company’s qualified ESPP program.
Positive
- None.
Negative
- None.
Insights
CEO executes sizable but partial open-market sale, retains large stake.
CEO Michael Hsing conducted open-market sales totaling 40,000 shares of Monolithic Power Systems common stock on May 18, 2026. The transactions were split across multiple price buckets between roughly $1,467 and $1,521 per share.
Following the sales, Hsing’s direct holdings stand at 879,020 shares, with additional indirect interests through two trusts. The filing shows no derivative exercises and an empty derivative position list, so this event reflects pure share disposals rather than an exercise-and-sell pattern.
Because the filing does not quantify the company’s total shares outstanding, the relative size of these trades versus the company’s equity base cannot be assessed here. From the data provided, this appears as a notable liquidity move by the CEO while maintaining a substantial continuing ownership position.
Insider Trade Summary
Net Seller: 40,000 shares ($59,310,169)
Net Sell
15 txns
Insider
Hsing Michael
Role
CEO
Sold
40,000 shs ($59.31M)
| Type | Security | Shares | Price | Value |
|---|---|---|---|---|
| Sale | Common Stock | 3,424 | $1,462.61 | $5.01M |
| Sale | Common Stock | 5,819 | $1,467.62 | $8.54M |
| Sale | Common Stock | 5,049 | $1,472.84 | $7.44M |
| Sale | Common Stock | 4,082 | $1,476.96 | $6.03M |
| Sale | Common Stock | 5,737 | $1,482.51 | $8.51M |
| Sale | Common Stock | 6,688 | $1,486.76 | $9.94M |
| Sale | Common Stock | 862 | $1,491.48 | $1.29M |
| Sale | Common Stock | 608 | $1,499.46 | $912K |
| Sale | Common Stock | 2,929 | $1,503.05 | $4.40M |
| Sale | Common Stock | 3,769 | $1,507.70 | $5.68M |
| Sale | Common Stock | 551 | $1,513.11 | $834K |
| Sale | Common Stock | 352 | $1,518.15 | $534K |
| Sale | Common Stock | 130 | $1,521.43 | $198K |
| holding | Common Stock | -- | -- | -- |
| holding | Common Stock | -- | -- | -- |
Holdings After Transaction:
Common Stock — 884,839 shares (Direct, null);
Common Stock — 133,040 shares (Indirect, by M Hsing 04 Trust)
Footnotes (1)
- Ending balance includes 29 shares acquired on February 17, 2026 through the Company's qualified ESPP program. 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 $1,459.96 to $1,464.86. 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. 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 $1,464.97 to $1,469.94. 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. 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 $1,469.95 to $1,474.94. 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. 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 $1,474.95 to $1,479.85. 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. 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 $1,479.99 to $1,484.93. 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. 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 $1,484.95 to $1,489.73. 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. 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 $1,490.17 to $1,494.10. 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. 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 $,1495.74 to $1,500.72. 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. 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 $1,500.75 to $1,505.70. 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. 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 $1,505.70 to $1,510.67. 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. 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 $1,510.68 to $1,515.44. 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. 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 $1,516.26 to $1,519.25. 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. 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 $1,521.33 to $1,521.56. 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: 40,000 shares
Direct holdings after sale: 879,020 shares
Indirect holdings ZH Family 2020 Trust: 12,825 shares
+4 more
7 metrics
Shares sold
40,000 shares
Total open-market sales on May 18, 2026
Direct holdings after sale
879,020 shares
Common stock held directly by CEO after transactions
Indirect holdings ZH Family 2020 Trust
12,825 shares
Common stock held indirectly via ZH Family 2020 Trust
Indirect holdings M Hsing 04 Trust
133,040 shares
Common stock held indirectly via M Hsing 04 Trust
Sample sale price
$1,521.43/share
One reported sale price for May 18, 2026 transactions
Sample sale price
$1,467.62/share
One reported sale price for May 18, 2026 transactions
ESPP shares included
29 shares
Acquired through qualified ESPP on February 17, 2026
Key Terms
open-market sale, weighted average sale price, qualified ESPP program, indirect ownership, +1 more
5 terms
open-market sale financial
"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.
weighted average sale price financial
"The price is the weighted average sale price for the transactions reported on this line."
qualified ESPP program financial
"shares acquired on February 17, 2026 through the Company's qualified ESPP program."
indirect ownership financial
"direct_or_indirect": "I", "nature_of_ownership": "ZH Family 2020 Trust""
Common Stock financial
""security_title": "Common Stock""
Common stock represents ownership shares in a company, giving investors a stake in its success and a say in important decisions through voting rights. It is the most common type of stock traded on markets and can provide income through dividends, as well as potential for value growth. For investors, holding common stock means sharing in the company’s profits and risks.
FAQ
Were the Monolithic Power Systems (MPWR) CEO transactions option exercises or pure sales?
The filing characterizes the CEO’s trades as open-market sales of common stock, coded “S” in the Form 4. The derivative section shows no option or warrant exercises, indicating these transactions were straightforward share disposals, not exercise-related.
What does the ESPP footnote in the Monolithic Power Systems (MPWR) Form 4 mean?
A footnote notes the ending balance includes 29 shares acquired through the company’s qualified ESPP program on February 17, 2026. This indicates a small portion of the CEO’s holdings comes from payroll-purchase plan participation.