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Katharine Weymouth

CIK 1501808 · last filed 2026-08-31

Katharine Weymouth is a corporate insider who has filed 112 SEC Form 4 insider transactions across 5 companies since 2010. The most recent filing, for XMTR, was dated Aug 31, 2026. Across all open-market trades the lifetime net is −$27.0M, making them a net seller over the disclosed history. Current disclosed insider exposure totals $14.6M across reported positions. 21 SEC filings were submitted jointly with Graham Holdings Co.

"Disclosed insider exposure" sums this person's most-recently-reported share counts across each company they're an insider in, multiplied by the current underlying price. It is not net worth — it misses retail holdings, private investments, real estate, index funds, and any company where the person isn't an SEC-reporting insider. For informational purposes only.

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Disclosed Exposure

$14.60M

Companies

5

Total Filings

112

Lifetime Open-Market Net

-$26.98M

Filer Profile

Reported Address
1812 NORTH MOORE STREET
SUITE 2100
ARLINGTON, VA 22209
Related Filers
Graham Holdings Co — 21 joint filings, latest 2026-05-28
Profile details as reported on the filer's SEC submissions — for individual insiders the address is often in care of the issuer. Related filers are identified from jointly filed SEC submissions and shared reported addresses. View filings on SEC EDGAR.

Holdings By Company

Latest on-record share count from this person's most recent non-derivative Form 4 transaction in each company. Disclosed exposure = shares × current underlying price.
Symbol Role Shares Price Disclosed Exposure Lifetime OM Net Filings Latest Filed
XMTR Director 43,960 $87.58 $3.85M -$810.6K 13 2026-08-31
RSG Director 8,138 $223.04 $1.82M -$774.9K 50 2026-07-17
GHC Director 7,615 $1159.75 $8.83M -$9.34M 11 2026-05-28
CABO Director 5,325 $18.63 $99.2K -$6.11M 26 2026-05-18
Graham Holdings Co (WPO) Delisted Director 19,721 — — -$9.94M 8 2013-10-11

Recent Filings

112 filings
Insider activity across all companies, newest first. Form 4 rows are post-trade confirmations (buys, sells, grants, exercises). Notice (144) rows are pre-trade notices of intent to sell restricted or control stock under Rule 144 — they may not all execute. Compare adjacent dates to see which notices became actual sales.
Filed Symbol Action Net Shares Net $ Link
2026-08-31 XMTR Notice (144) −5,000 -$476.1K EDGAR
2026-08-31 XMTR Mixed — -$903.1K EDGAR
2026-08-28 XMTR Notice (144) −5,000 -$471.5K EDGAR
2026-07-17 RSG Grant (A) — $0 EDGAR
2026-05-28 GHC Other (J) +6,000 $0 EDGAR
2026-05-18 CABO Grant (A) +3,031 $155.0K EDGAR
2026-04-17 RSG Grant (A) — $0 EDGAR
2026-03-12 XMTR Grant (A) +5,037 $0 EDGAR
2026-03-02 XMTR Buy (P) +1,215 $50.0K EDGAR
2026-02-03 RSG Exer (M) +1,858 $0 EDGAR
Showing 1–10 of 112
Page 1 of 12
Form 4 codes: P = open-market purchase · S = open-market sale · A = grant/award · M = option exercise · F = tax withholding at vest · G = bona-fide gift · D = disposition to issuer · J = other (see filing footnote). Only P / S codes carry directional signal.
Notice (144 / 144/A): Form 144 is a notice of intent to sell restricted/control stock under Rule 144, filed before the sale; 144/A is an amendment. Many notices are pre-scheduled under Rule 10b5-1 plans. A Form 4 with code S typically follows within a few days when the planned sale executes; missing follow-up Form 4s suggest the notice was cancelled or modified.