Severin Hacker

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

"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.

Loading insider history…
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 $133.60 $9.6K -$225.09M 73 2026-05-29

Recent Filings · Page 8 of 9

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
2022-09-06 DUOL Mixed -$920.9K EDGAR
2022-08-02 DUOL Mixed -$942.6K EDGAR
2022-07-05 DUOL Mixed -$912.2K EDGAR
2022-06-27 DUOL Mixed -$1.97M EDGAR
2022-06-21 DUOL Mixed -$1.83M EDGAR
2022-06-13 DUOL Mixed -$1.96M EDGAR
2022-06-03 DUOL Mixed -$1.66M EDGAR
2022-02-10 DUOL Mixed $0 EDGAR
2021-12-10 DUOL Mixed +72 -$4.0K EDGAR
2021-11-17 DUOL Mixed -$4.33M EDGAR
Showing 7180 of 82
Page 8 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.