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David T Howton

CIK 1529297 · Chief Operating Officer · last filed 2026-04-21

David T Howton is a Chief Operating Officer who has filed 45 SEC Form 4 insider transactions across 3 companies since 2011. The most recent filing, for SLDB, was dated Apr 21, 2026. Across all open-market trades the lifetime net is −$43.8M, making them a net seller over the disclosed history. Current disclosed insider exposure totals $13.5M 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

$13.47M

Companies

3

Total Filings

45

Lifetime Open-Market Net

-$43.82M

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
SLDB Chief Operating Officer 105,077 $8.56 $899.5K -$498.9K 12 2026-04-21
SRPT EVP, General Counsel 130,984 $17.18 $2.25M -$43.31M 26 2020-06-22
VRTX SVP & Chief Legal Officer 19,703 $523.91 $10.32M -$14.5K 2 2012-02-06

Recent Filings

45 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
2026-04-21 SLDB Grant (A) — $0 EDGAR
2026-02-18 SLDB Mixed +7,218 -$43.5K EDGAR
2026-02-18 SLDB Notice (144) −7,469 -$43.5K EDGAR
2026-02-06 SLDB Sell (S) −18,894 -$121.7K EDGAR
2026-02-04 SLDB Notice (144) −18,894 -$121.7K EDGAR
2026-02-02 SLDB Mixed +83,845 -$243.1K EDGAR
2026-02-02 SLDB Notice (144) −37,771 -$243.1K EDGAR
2025-12-04 SLDB Mixed +8,119 -$25.2K EDGAR
2025-08-18 SLDB Grant (A) — $0 EDGAR
2025-02-18 SLDB Mixed +9,126 -$22.0K EDGAR
Showing 1–10 of 45
Page 1 of 5
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.