Hsing Michael, CEO of Monolithic Power Systems (MPWR), has filed 102 Form 4 transactions, all of them sales. The total sell value is $369.4 million, with zero open-market purchases and zero acquisitions through grants or option exercises in the data set. The pattern is one-directional: every reported trade is an open-market sale (code S), and the 25 most recent trades, all in MPWR, are sales as well.
The recent activity clusters on three dates. On September 28, 2026, Hsing filed eight sales totaling roughly $39.3 million, with individual values ranging from $176,402 to $14.8 million. On May 18, 2026, he filed 13 sales totaling about $55.4 million, with the largest single transaction at $9.94 million. On February 12, 2026, four sales added up to about $8.3 million, the smallest being $716,604. The dollar amounts are large and consistent with a CEO liquidating a substantial portion of holdings, but the filings do not indicate whether the sales were part of a prearranged 10b5-1 plan.
No purchases appear anywhere in the record. The absence of code P transactions, combined with the concentration of sales in a single ticker, shows a sustained selling bias across the period covered. The most recent filing date, September 28, 2026, is the heaviest single day by total value among the recent trades, with over $39 million sold. The data does not include any transactions coded as gifts, tax withholdings, or option exercises, so the selling is direct and open-market in nature.
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