MPWR MONOLITHIC POWER SYSTEMS INC Insider Trading

EVP & General Counsel Saria Tseng sold 7,565 shares of MPWR at $1,700.00 for $12,860,500.00

Saria Tseng, EVP & General Counsel of Monolithic Power Systems, sold 7,565 shares on 2026-05-27 at $1,700.00, reducing her holdings by 5.0% to 144,218 shares. The sale occurred when MPWR was trading near its 52-week high ($1,714.09), and the stock has since declined 8.6% to the current price of $1,566.21. Across her prior five sells at MPWR, none were well-timed at the 90-day horizon (all showed positive subsequent returns), and her cross-ticker track record shows a 0.00% well-timed rate on 20 prior sells with average 90-day returns of +36.2%, suggesting a consistent pattern of selling before rallies rather than downturns. Against the company's strong fundamentals—$804.2M quarterly revenue, +26.4% annual growth, and $193.2M net income—this sale by a senior legal executive, while modest in percentage terms, occurs in context of the stock's elevated valuation (P/E of 113.00) and near historical highs.

EVP General Counsel Saria Tseng sold 5,000 MPWR shares at $1,586.43 for $7.9M on 2026-05-22.

Saria Tseng sold 5,000 shares representing a 3.2% reduction of her 156,783-share position at $1,586.43 on 2026-05-22, generating $7,932,150.00 in proceeds. The insider retains substantial holdings of 151,783 shares post-transaction, suggesting continued equity exposure. Her five prior sales at MPWR (all on 2026-04-08) were followed by 90-day returns ranging from +25.8% to +31.3%, with none representing profitable exit timing (for sells, negative post-transaction returns indicate well-timed sales; her 0.00% same-ticker well-timed rate shows zero instances of selling before declines). The current price of $1,620.17 is -5.5% below the 52-week high of $1,714.09, and the stock has risen 2.0% over 30 days and 37.3% over 90 days—post-transaction the stock has continued to appreciate beyond the sale price.

CEO Hsing Michael sold 40,000 shares of MPWR for $59,310,168.55 across 13 transactions on 2026-05-18

CEO Hsing Michael executed 13 separate sales totaling 40,000 shares for $59,310,168.55 on 2026-05-18, reducing holdings from 888,263 to 848,263 shares. The transaction occurred at prices ranging from $1,462.61 to $1,521.43, with a blended average of $1,482.75, while the current price stands at $1,553.27. Examining his same-ticker history at MPWR reveals 5 prior sales on 2026-02-12, none of which were well-timed at the 90-day mark—all generated positive average 90-day returns of +35.6% to +42.3%, indicating the stock subsequently rose after those sales. His cross-ticker track record shows 20 prior sells with a 0.00% well-timed rate at 90 days and an average 90-day return of +37.8%, further indicating a pattern where his prior sales have been followed by stock appreciation rather than declines.

EVP Sciammas sold 12,000 shares at blended $1,561.40 on 2026-05-15 via 10b5-1 plan

Maurice Sciammas, EVP of Worldwide Sales & Marketing, executed 8 separate sales totaling 12,000 shares for $18,736,849.52 under a pre-arranged 10b5-1 trading plan. The scheduled nature of the transaction removes timing as an inference variable. His prior sales at MPWR over recent months (November–February 2026) showed 90-day returns of +33.2% to +34.6%, indicating the stock generally moved upward following his sales. This filing reduces his holding from 178,644 to 166,644 shares (-6.7%). The company trades at a P/E of 105.92 on $804.2M quarterly revenue with +26.4% annual growth, reflecting elevated valuation in a high-growth category; the current price of $1,468.11 is -12.4% from the 52-week high of $1,675.42.

Director Elmiger sells $19M in MPWR shares across nine transactions on single day; historically all prior sells were poorly timed.

Elmiger Eugen J, a director at Monolithic Power Systems, executed a large block disposal of approximately $19 million in shares on a single day, dispersing the transaction across nine separate sales. While the absolute dollar value is substantial, it represented a measured reduction of his holdings rather than a panic exit—his largest single sale accounted for less than one-third of his position. The stock is currently trading modestly below its 52-week high and has rallied sharply over the past quarter, establishing a price environment that could reasonably prompt profit-taking activity. However, Elmiger's prior selling history at this specific company is noteworthy: every previous sale he made saw the stock rise afterward, meaning all of his prior exits were poorly timed. This pattern creates a credibility challenge for the current transaction—an insider whose prior sells preceded gains cannot claim to be a reliable market timer at this company. The company remains profitable with growing revenue, so the fundamentals do not obviously suggest a need to de-risk, yet the director's historical track record on timing argues for caution about reading too much into this particular seller's judgment.

EVP Xiao Deming sold 30,000 shares (~$49.6M) in single-day transaction; 6th consecutive sale at MPWR with mixed prior timing.

Xiao Deming, EVP of Global Operations, disposed of 30,000 shares in four separate transactions on the same day, raising approximately $49.6 million at prices near the 52-week high. This represents the sixth consecutive open-market sale at MPWR by this executive—a long stretch of one-directional activity with no offsetting purchases over a three-year window. His prior five sales at this ticker showed mixed timing results: three preceded stock declines (well-timed exits) while two were followed by appreciable gains (poorly-timed exits), indicating inconsistent judgment about when to exit. The company remains profitable with growing revenue, so the sale does not appear to stem from fundamental deterioration; the stock is trading near its 52-week high after rallying significantly over the past three months. The sheer volume and repeated sale pattern warrant monitoring, though the mixed track record on prior exits—combined with trading near recent highs—limits the degree of conviction this filing alone conveys.

Director Zhou Jeff sold approximately 1,514 shares across three transactions totaling $2.43M, reducing stake by 8.9-10.4%.

Director Zhou Jeff executed a series of three sales over two trading days, offloading roughly $2.4 million in Monolithic Power Systems stock while the shares trade near their 52-week highs. The sales represent a meaningful reduction in his director stake, with each transaction trimming his holdings by single-digit to low-double-digit percentages. The company itself remains solidly profitable with strong revenue growth, suggesting the sales reflect a rebalancing decision rather than distress or lost confidence in the business. The timing coincides with the stock in a strong price position following a significant rally, which is a typical window for insider liquidation unrelated to fundamental concerns.