Bruce Booth

CIK 1451612 · last filed 2026-07-02

Bruce Booth is a corporate insider who has filed 86 SEC Form 4 insider transactions across 8 companies since 2015. The most recent filing shows the insider sold $8.3M of KYMR on Jul 2, 2026. Across all open-market trades the lifetime net is −$248.0M, making them a net seller over the disclosed history. Current disclosed insider exposure totals $71.9M across reported positions.

"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

$71.89M

Companies

8

Total Filings

86

Lifetime Open-Market Net

-$248.00M

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
KYMR Director 475,805 $119.05 $56.64M -$263.36M 27 2026-07-02
SION Director 2,360,156 $6.46 $15.25M -$21.01M 8 2026-06-18
Vigil Neuroscience, Inc. (VIGL) Delisted Director 0 $8.05 $0 $7.49M 11 2025-08-05
Tectonic Therapeutic, Inc. (AVRO) Delisted Director 463,941 $16.80 $7.79M $15.00M 7 2023-06-08
Dianthus Therapeutics, Inc. /DE/ (MGTA) Delisted Director 257,320 $11.19 $2.88M $9.75M 7 2022-06-30
Cogent Biosciences, Inc. (UMRX) Delisted Director 3,184,446 $1.13M 12 2020-07-06
Viridian Therapeutics, Inc.\DE (MGEN) Delisted Director 209,505 $3.00M 5 2018-06-28
Larimar Therapeutics, Inc. (ZFGN) Delisted Director 386,502 $0 7 2018-01-05

Recent Filings

86 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
2026-07-02 KYMR Sell (S) −76,650 -$8.28M EDGAR
2026-06-25 KYMR Sell (S) −285,684 -$34.81M EDGAR
2026-06-25 KYMR Sell (S) −398,765 -$43.99M EDGAR
2026-06-25 KYMR Grant (A) $0 EDGAR
2026-06-22 KYMR Sell (S) −31,798 -$3.30M EDGAR
2026-06-22 KYMR Mixed −466,457 -$45.06M EDGAR
2026-06-18 SION Grant (A) $0 EDGAR
2026-06-17 KYMR Notice (144) −11,741 -$1.03M EDGAR
2026-04-24 KYMR Mixed −100 -$454.6K EDGAR
2026-04-16 KYMR Mixed −3,135 -$764.4K EDGAR
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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.