Recent insider transactions reported to the SEC on Form 4 — directors and officers buying or selling their own company’s stock. Sourced directly from public SEC filings, latest filed Oct 8, 2026.
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Counts cover the 100 most recent Form 4 filings Tradune holds for TSM (filed Aug 10 – Oct 8, 2026). No completed check of TSM's Form 4 list on SEC EDGAR is on record yet; the latest TSM filing Tradune holds was filed Oct 8, 2026. This is not guaranteed to be the complete record — see TSM's full Form 4 filing history on SEC EDGAR.
Open-market activity, 100 most recent filings
Purchases (Form 4 code P) and sales (code S) on the 100 filings Tradune holds for TSM filed Aug 10 – Oct 8, 2026 — the most recent 100 held, so older filings from the last 90 days may be missing. Grants, exercises, tax withholding and the other Form 4 transaction codes are left out.
Open-market purchases and sales by insider
Insider
Buys
Sells
Shares bought
Shares sold
Lipen YuanVP
6
0
2,473
—
Bor-Zen TienVP
6
0
144
—
Shu-Hua FangSVP and GC
3
0
1,109
—
Che-Chia WeiChairman and CEO
3
0
445
—
Yuh-Jier MiiEVP and Co-COO
3
0
211
—
Kevin Xiaoqiang ZhangSVP and Deputy Co-COO
3
0
183
—
Shien-Yang WuSVP
3
0
167
—
Choh Fei YeapSVP
3
0
163
—
Kuo-Chin HsuVP
3
0
161
—
Ying-Lang WangSVP
3
0
161
—
Showing the 10 most active of 30 insiders. Dollar value: value undisclosed — the filings held may not cover the full 90 days, so totals are not shown.
Summarises ~90 days of public SEC Form 4 activity — more distinct buyers, officer involvement and net buying score higher. A description of filing activity, not a rating or buy signal. How this score is computed →
Weekly signal history
TSM appeared in 9 archived weekly editions as a multi-insider cluster, a top net buyer, or both. These are frozen weekly snapshots, not a complete filing history.
An entry means this company met that edition’s displayed cluster or top-buyer threshold. Missing weeks do not mean no insider transaction occurred. All figures are derived from SEC Form 4 filings; open-market buys minus sales are shown as net only when every transaction value was disclosed.
How to read this: an open-market purchase (Form 4 code P) is a buy at the market price with the insider’s own money, as opposed to a grant, award or option exercise; an open-market sale is code S. When two or more distinct insiders report open-market purchases in the same 90-day window, this site labels that a cluster — a definition, not a forecast; see insider cluster buying.
“Held after” is Form 4 Table I column 5; “Change” = shares ÷ holdings before the trade (held after − shares for an acquisition, held after + shares for a disposition).
Insider Buying at TSM
Insiders reported 84 open-market purchases of TSM in the trailing 90 days, across 30 distinct buyers.
The most recent purchase was reported by Chih-Ho Chen (Controller) on Oct 7, 2026.
Grants, option exercises, and tax-withholding transactions are excluded from these counts.
† change in this filer’s own reported holding line (Form 4 Table I, col. 5), not of total company ownership; small prior holdings produce large percentages, so under 100 shares the prior holding is shown instead.
“10b5-1 box checked” = the filer checked the Form 4 box stating that a transaction on the filing was made under a plan intended to satisfy Rule 10b5-1(c); “10b5-1 box not checked” = the box was left blank, which does not prove that no plan exists. The box applies to Form 4s filed from April 1, 2023; older filings, and boxes we could not read, carry no tag. What the 10b5-1 box means.
Listing the 25 most recent of 100 Form 4 filings held for TSM; the 75 older filings (filed Aug 10 – Oct 8, 2026) are counted above but not listed here — see TSM's full Form 4 filing history on SEC EDGAR.
Insider filings reported around the same time
Other companies whose most recent Form 4 was filed closest to TSM's (Oct 8, 2026).
How many insiders bought TSM stock in the last 90 days?
30 distinct insiders at Taiwan Semiconductor reported 84 open-market purchases (Form 4 code P) of TSM shares in the trailing 90 days, the most recent filed by Chih-Ho Chen (Controller) on Oct 7, 2026. Grants, option exercises, and tax-withholding transactions are excluded from these counts.
Who filed the most recent Form 4 for TSM?
The most recent Form 4 on this page was filed by Chih-Ho Chen (Controller) on Oct 8, 2026, reporting 1 transaction. The original document is linked from the filing list above on SEC EDGAR. Amended filings (Form 4/A) may later revise reported figures.
What was the largest open-market TSM insider purchase shown?
The largest open-market purchase among the filings shown was 1,000 TSM shares at $77.09 (about $77,090) by Shu-Hua Fang (SVP and GC) on Jul 2, 2026. Value is shares × the price reported on the Form 4; trades may be made under a prearranged Rule 10b5-1 plan.
New to Form 4s? The transaction codes, the 90-day window and the 0–100 score are defined on the insider-activity score methodology page.
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This score summarizes SEC Form 4 filing activity over the trailing 90 days. It is descriptive, not predictive — not a rating, recommendation, or investment advice. Data: SEC EDGAR (public domain), as filed; amendments may revise figures. Tradune is not a registered investment adviser.
Data as filed; amended filings (Form 4/A) may revise figures. Sales may occur under prearranged Rule 10b5-1 trading plans.