What the executives and directors of Monolithic Power Systems actually did with their own shares, decoded from three years of SEC Form 4 filings.

The tape: three years of insider trades

Every marker sits at the exact price reported on the Form 4. The line is the monthly median of all prices insiders reported, so the chart needs no market feed; the gray strip is routine flow (vestings, tax withholding, gifts) that headlines love to miscount as selling.

Where the shares went, last 12 months

Every Form 4 movement decomposed: what flowed in (grants, vested equity, purchases) and what flowed out (tax withholding, plan sales, discretionary sales, gifts). Counted in shares, because grants carry no price.

Skin in the game

Directly held shares as reported after each trade, indexed to 100 five years back. Direct holdings only: trust and family-entity positions are per-entity in the filings and do not sum honestly, so this chart refuses to guess. The steps are the trades.

Who holds what

Open-market trade log

“Since trade” compares with the latest insider-implied price, not a market quote; this site carries no market data by design.

Filing hygiene

How to read this

A Form 4 transaction code decides everything. P is an open-market purchase and S an open-market sale; those two are the only codes where an insider chose to trade. A is a grant, M an option exercise or vesting, F shares withheld to cover tax, G a gift. Most “insiders dumped billions” headlines are code F and M mechanics.

Sales flagged 10b5-1 run on a plan the insider adopted in advance; since 2023 every Form 4 carries that flag. Buys have historically predicted returns, sales mostly have not, and this page states filings, not advice.

Every number on this page comes from Forms 3, 4 and 5 filed with the SEC, refreshed daily. Browse the source filings on SEC EDGAR. Data through 2026-08-06