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Severin Hacker

CIK 1870272 · Chief Tech Officer, Co-Founder · last filed 2026-05-29

Severin Hacker is a Chief Tech Officer, Co-Founder who has filed 82 SEC Form 4 insider transactions across 1 company since 2021. The most recent filing, for DUOL, was dated May 29, 2026. Across all open-market trades the lifetime net is −$225.1M, making them a net seller over the disclosed history. Current disclosed insider exposure totals $9.6K 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

$9.6K

Companies

1

Total Filings

82

Lifetime Open-Market Net

-$225.09M

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
DUOL Chief Tech Officer, Co-Founder 72 $132.75 $9.6K -$225.09M 73 2026-05-29

Recent Filings

82 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
2026-05-29 DUOL Mixed — $0 EDGAR
2026-02-20 DUOL Mixed — $0 EDGAR
2025-12-09 DUOL Mixed — $0 EDGAR
2025-12-03 DUOL Mixed — $0 EDGAR
2025-11-20 DUOL Mixed — -$1.35M EDGAR
2025-11-06 DUOL Mixed — -$2.25M EDGAR
2025-10-22 DUOL Mixed — -$2.77M EDGAR
2025-10-07 DUOL Mixed — -$2.84M EDGAR
2025-10-06 DUOL Notice (144) −40,000 -$12.91M EDGAR
2025-09-22 DUOL Mixed — -$2.51M EDGAR
Showing 1–10 of 82
Page 1 of 9
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.