Hacker Severin

Insider

Chief Tech Officer, Co-Founder

Trades at: DUOL

30D 90D 1Y

Net shares · 365d

-100.0K

0 buy · 100.0K sell

Net value · 365d

-$30.7M

$0 in · $30.7M out

Sentiment · 365d

Net selling

0% buying · 100% selling

Open-market trades · 365d

108

0 buy · 100.0K sell

Trading track record · all companies

Running net of open-market buys − sells across every company. Tap the line or a marker for details. ▲ buy · ▼ sell.

Transactions · 365d

Open-market Buys Sells All types

DUOL Other·F
May 27, 26

Chief Tech Officer, Co-Founder

$3.4M

31.9K sh · $107.82

Own -13%
DUOL Exercise·M
May 27, 26

Chief Tech Officer, Co-Founder

$0

120.0K sh · 2 lots

Own +102%
DUOL Other·F
Feb 17, 26

Chief Tech Officer, Co-Founder

$3.4M

30.6K sh · $112.57

Own -15%
DUOL Exercise·M
Feb 17, 26

Chief Tech Officer, Co-Founder

$0

120.0K sh · 2 lots

Own +137%
DUOL Exercise·C
Dec 8, 25

Chief Tech Officer, Co-Founder

$0

50.0K sh

Own +2%
DUOL Exercise·C
Dec 8, 25

Chief Tech Officer, Co-Founder

$0

50.0K sh

Own +69444%
DUOL Other·G
Dec 8, 25

Chief Tech Officer, Co-Founder

$0

50.0K sh

Own -100%
DUOL Exercise·M
Dec 3, 25

Chief Tech Officer, Co-Founder

$200.0K

130.5K sh · $1.53 avg · 4 lots

Own +755%
DUOL Other·F
Dec 1, 25

Chief Tech Officer, Co-Founder

$5.9M

31.8K sh · $185.45

Own -18%
DUOL Exercise·C
Nov 19, 25

Chief Tech Officer, Co-Founder · 10b5-1

$0

20.0K sh · 2 lots

Own +21%
DUOL Exercise·M
Nov 19, 25

Chief Tech Officer, Co-Founder · 10b5-1

$0

10.0K sh

Own New
DUOL Sell·S
Nov 19, 25

Chief Tech Officer, Co-Founder · 10b5-1

$1.7M

10.0K sh · $172.75 avg · 8 lots

Own -99%
DUOL Exercise·C
Nov 19, 25

Chief Tech Officer, Co-Founder · 10b5-1

$380.8K

10.0K sh · $38.08

Own +13889%
DUOL Exercise·C
Nov 4, 25

Chief Tech Officer, Co-Founder · 10b5-1

$0

20.0K sh · 2 lots

Own +21%
DUOL Exercise·M
Nov 4, 25

Chief Tech Officer, Co-Founder · 10b5-1

$0

10.0K sh

Own +190%
DUOL Sell·S
Nov 4, 25

Chief Tech Officer, Co-Founder · 10b5-1

$2.6M

10.0K sh · $263.13 avg · 10 lots

Own -63%
DUOL Exercise·C
Nov 4, 25

Chief Tech Officer, Co-Founder · 10b5-1

$380.8K

10.0K sh · $38.08

Own +13889%
DUOL Exercise·M
Oct 20, 25

Chief Tech Officer, Co-Founder · 10b5-1

$0

130.0K sh · 3 lots

Own +50%
DUOL Exercise·C
Oct 20, 25

Chief Tech Officer, Co-Founder · 10b5-1

$0

20.0K sh · 2 lots

Own +26%
DUOL Other·F
Oct 20, 25

Chief Tech Officer, Co-Founder · 10b5-1

$9.9M

31.8K sh · $312.73

Own -22%
DUOL Sell·S
Oct 20, 25

Chief Tech Officer, Co-Founder · 10b5-1

$3.1M

10.0K sh · $314.72 avg · 15 lots

Own -83%
DUOL Exercise·C
Oct 20, 25

Chief Tech Officer, Co-Founder · 10b5-1

$380.8K

10.0K sh · $38.08

Own +13889%
DUOL Exercise·C
Oct 6, 25

Chief Tech Officer, Co-Founder · 10b5-1

$0

20.0K sh · 2 lots

Own +30%
DUOL Exercise·M
Oct 6, 25

Chief Tech Officer, Co-Founder · 10b5-1

$0

10.0K sh

Own +40%
DUOL Sell·S
Oct 6, 25

Chief Tech Officer, Co-Founder · 10b5-1

$3.2M

10.0K sh · $321.63 avg · 11 lots

Own -51%
DUOL Exercise·C
Oct 6, 25

Chief Tech Officer, Co-Founder · 10b5-1

$380.8K

10.0K sh · $38.08

Own +13889%
DUOL Exercise·C
Sep 19, 25

Chief Tech Officer, Co-Founder · 10b5-1

$0

20.0K sh · 2 lots

Own +26%
DUOL Exercise·M
Sep 19, 25

Chief Tech Officer, Co-Founder · 10b5-1

$0

10.0K sh

Own +28%
DUOL Sell·S
Sep 19, 25

Chief Tech Officer, Co-Founder · 10b5-1

$2.9M

10.0K sh · $288.93 avg · 5 lots

Own -61%
DUOL Exercise·C
Sep 19, 25

Chief Tech Officer, Co-Founder · 10b5-1

$380.8K

10.0K sh · $38.08

Own +13889%
DUOL Exercise·C
Sep 5, 25

Chief Tech Officer, Co-Founder · 10b5-1

$0

20.0K sh · 2 lots

Own +26%
DUOL Exercise·M
Sep 5, 25

Chief Tech Officer, Co-Founder · 10b5-1

$0

10.0K sh

Own +22%
DUOL Sell·S
Sep 5, 25

Chief Tech Officer, Co-Founder · 10b5-1

$2.7M

10.0K sh · $268.55 avg · 8 lots

Own -65%
DUOL Exercise·C
Sep 5, 25

Chief Tech Officer, Co-Founder · 10b5-1

$380.8K

10.0K sh · $38.08

Own +13889%
DUOL Exercise·C
Aug 20, 25

Chief Tech Officer, Co-Founder

$0

10.0K sh

Own +0%
DUOL Other·G
Aug 20, 25

Chief Tech Officer, Co-Founder

$0

10.0K sh

Own -100%
DUOL Exercise·C
Aug 20, 25

Chief Tech Officer, Co-Founder

$0

10.0K sh

Own New
DUOL Exercise·M
Aug 19, 25

Chief Tech Officer, Co-Founder · 10b5-1

$0

10.0K sh

Own +18%
DUOL Exercise·C
Aug 19, 25

Chief Tech Officer, Co-Founder · 10b5-1

$0

20.0K sh · 2 lots

Own +26%
DUOL Sell·S
Aug 19, 25

Chief Tech Officer, Co-Founder · 10b5-1

$3.4M

10.0K sh · $344.56 avg · 17 lots

Own -52%
DUOL Exercise·C
Aug 19, 25

Chief Tech Officer, Co-Founder · 10b5-1

$380.8K

10.0K sh · $38.08

Own +13889%
DUOL Exercise·C
Aug 5, 25

Chief Tech Officer, Co-Founder · 10b5-1

$0

20.0K sh · 2 lots

Own +30%
DUOL Exercise·M
Aug 5, 25

Chief Tech Officer, Co-Founder · 10b5-1

$0

10.0K sh

Own +15%
DUOL Sell·S
Aug 5, 25

Chief Tech Officer, Co-Founder · 10b5-1

$3.4M

10.0K sh · $344.41 avg · 12 lots

Own -81%
DUOL Exercise·C
Aug 5, 25

Chief Tech Officer, Co-Founder · 10b5-1

$380.8K

10.0K sh · $38.08

Own +13889%
DUOL Exercise·C
Jul 21, 25

Chief Tech Officer, Co-Founder · 10b5-1

$0

20.0K sh · 2 lots

Own +26%
DUOL Exercise·M
Jul 21, 25

Chief Tech Officer, Co-Founder · 10b5-1

$0

10.0K sh

Own +13%
DUOL Sell·S
Jul 21, 25

Chief Tech Officer, Co-Founder · 10b5-1

$3.6M

10.0K sh · $360.33 avg · 13 lots

Own -94%
DUOL Exercise·C
Jul 21, 25

Chief Tech Officer, Co-Founder · 10b5-1

$380.8K

10.0K sh · $38.08

Own +13889%
DUOL Exercise·C
Jul 7, 25

Chief Tech Officer, Co-Founder · 10b5-1

$0

20.0K sh · 2 lots

Own +26%
DUOL Exercise·M
Jul 7, 25

Chief Tech Officer, Co-Founder · 10b5-1

$0

10.0K sh

Own +12%
DUOL Sell·S
Jul 7, 25

Chief Tech Officer, Co-Founder · 10b5-1

$3.9M

10.0K sh · $392.89 avg · 9 lots

Own -50%
DUOL Exercise·C
Jul 7, 25

Chief Tech Officer, Co-Founder · 10b5-1

$380.8K

10.0K sh · $38.08

Own +13889%

Date▾	Ticker	Role	Type	Shares	Own Δ	Price	Value
May 27, 2026	DUOL	Chief Tech Officer, Co-Founder	Other F	31.9K	-13%	$107.82	$3.4M
May 27, 2026	DUOL	Chief Tech Officer, Co-Founder	Exercise M	120.0K2 lots	+102%	—	$0
Feb 17, 2026	DUOL	Chief Tech Officer, Co-Founder	Other F	30.6K	-15%	$112.57	$3.4M
Feb 17, 2026	DUOL	Chief Tech Officer, Co-Founder	Exercise M	120.0K2 lots	+137%	—	$0
Dec 8, 2025	DUOL	Chief Tech Officer, Co-Founder	Exercise C	50.0K	+2%	—	$0
Dec 8, 2025	DUOL	Chief Tech Officer, Co-Founder	Exercise C	50.0K	+69444%	—	$0
Dec 8, 2025	DUOL	Chief Tech Officer, Co-Founder	Other G	50.0K	-100%	—	$0
Dec 3, 2025	DUOL	Chief Tech Officer, Co-Founder	Exercise M	130.5K4 lots	+755%	$1.53 avg	$200.0K
Dec 1, 2025	DUOL	Chief Tech Officer, Co-Founder	Other F	31.8K	-18%	$185.45	$5.9M
Nov 19, 2025	DUOL	Chief Tech Officer, Co-Founder	Exercise C	20.0K2 lots	+21%	—	$0
Nov 19, 2025	DUOL	Chief Tech Officer, Co-Founder	Exercise M	10.0K	New	—	$0
Nov 19, 2025	DUOL	Chief Tech Officer, Co-Founder	Sell S	10.0K8 lots	-99%	$172.75 avg	$1.7M
Nov 19, 2025	DUOL	Chief Tech Officer, Co-Founder	Exercise C	10.0K	+13889%	$38.08	$380.8K
Nov 4, 2025	DUOL	Chief Tech Officer, Co-Founder	Exercise C	20.0K2 lots	+21%	—	$0
Nov 4, 2025	DUOL	Chief Tech Officer, Co-Founder	Exercise M	10.0K	+190%	—	$0
Nov 4, 2025	DUOL	Chief Tech Officer, Co-Founder	Sell S	10.0K10 lots	-63%	$263.13 avg	$2.6M
Nov 4, 2025	DUOL	Chief Tech Officer, Co-Founder	Exercise C	10.0K	+13889%	$38.08	$380.8K
Oct 20, 2025	DUOL	Chief Tech Officer, Co-Founder	Exercise M	130.0K3 lots	+50%	—	$0
Oct 20, 2025	DUOL	Chief Tech Officer, Co-Founder	Exercise C	20.0K2 lots	+26%	—	$0
Oct 20, 2025	DUOL	Chief Tech Officer, Co-Founder	Other F	31.8K	-22%	$312.73	$9.9M
Oct 20, 2025	DUOL	Chief Tech Officer, Co-Founder	Sell S	10.0K15 lots	-83%	$314.72 avg	$3.1M
Oct 20, 2025	DUOL	Chief Tech Officer, Co-Founder	Exercise C	10.0K	+13889%	$38.08	$380.8K
Oct 6, 2025	DUOL	Chief Tech Officer, Co-Founder	Exercise C	20.0K2 lots	+30%	—	$0
Oct 6, 2025	DUOL	Chief Tech Officer, Co-Founder	Exercise M	10.0K	+40%	—	$0
Oct 6, 2025	DUOL	Chief Tech Officer, Co-Founder	Sell S	10.0K11 lots	-51%	$321.63 avg	$3.2M
Oct 6, 2025	DUOL	Chief Tech Officer, Co-Founder	Exercise C	10.0K	+13889%	$38.08	$380.8K
Sep 19, 2025	DUOL	Chief Tech Officer, Co-Founder	Exercise C	20.0K2 lots	+26%	—	$0
Sep 19, 2025	DUOL	Chief Tech Officer, Co-Founder	Exercise M	10.0K	+28%	—	$0
Sep 19, 2025	DUOL	Chief Tech Officer, Co-Founder	Sell S	10.0K5 lots	-61%	$288.93 avg	$2.9M
Sep 19, 2025	DUOL	Chief Tech Officer, Co-Founder	Exercise C	10.0K	+13889%	$38.08	$380.8K
Sep 5, 2025	DUOL	Chief Tech Officer, Co-Founder	Exercise C	20.0K2 lots	+26%	—	$0
Sep 5, 2025	DUOL	Chief Tech Officer, Co-Founder	Exercise M	10.0K	+22%	—	$0
Sep 5, 2025	DUOL	Chief Tech Officer, Co-Founder	Sell S	10.0K8 lots	-65%	$268.55 avg	$2.7M
Sep 5, 2025	DUOL	Chief Tech Officer, Co-Founder	Exercise C	10.0K	+13889%	$38.08	$380.8K
Aug 20, 2025	DUOL	Chief Tech Officer, Co-Founder	Exercise C	10.0K	+0%	—	$0
Aug 20, 2025	DUOL	Chief Tech Officer, Co-Founder	Other G	10.0K	-100%	—	$0
Aug 20, 2025	DUOL	Chief Tech Officer, Co-Founder	Exercise C	10.0K	New	—	$0
Aug 19, 2025	DUOL	Chief Tech Officer, Co-Founder	Exercise M	10.0K	+18%	—	$0
Aug 19, 2025	DUOL	Chief Tech Officer, Co-Founder	Exercise C	20.0K2 lots	+26%	—	$0
Aug 19, 2025	DUOL	Chief Tech Officer, Co-Founder	Sell S	10.0K17 lots	-52%	$344.56 avg	$3.4M
Aug 19, 2025	DUOL	Chief Tech Officer, Co-Founder	Exercise C	10.0K	+13889%	$38.08	$380.8K
Aug 5, 2025	DUOL	Chief Tech Officer, Co-Founder	Exercise C	20.0K2 lots	+30%	—	$0
Aug 5, 2025	DUOL	Chief Tech Officer, Co-Founder	Exercise M	10.0K	+15%	—	$0
Aug 5, 2025	DUOL	Chief Tech Officer, Co-Founder	Sell S	10.0K12 lots	-81%	$344.41 avg	$3.4M
Aug 5, 2025	DUOL	Chief Tech Officer, Co-Founder	Exercise C	10.0K	+13889%	$38.08	$380.8K
Jul 21, 2025	DUOL	Chief Tech Officer, Co-Founder	Exercise C	20.0K2 lots	+26%	—	$0
Jul 21, 2025	DUOL	Chief Tech Officer, Co-Founder	Exercise M	10.0K	+13%	—	$0
Jul 21, 2025	DUOL	Chief Tech Officer, Co-Founder	Sell S	10.0K13 lots	-94%	$360.33 avg	$3.6M
Jul 21, 2025	DUOL	Chief Tech Officer, Co-Founder	Exercise C	10.0K	+13889%	$38.08	$380.8K
Jul 7, 2025	DUOL	Chief Tech Officer, Co-Founder	Exercise C	20.0K2 lots	+26%	—	$0
Jul 7, 2025	DUOL	Chief Tech Officer, Co-Founder	Exercise M	10.0K	+12%	—	$0
Jul 7, 2025	DUOL	Chief Tech Officer, Co-Founder	Sell S	10.0K9 lots	-50%	$392.89 avg	$3.9M
Jul 7, 2025	DUOL	Chief Tech Officer, Co-Founder	Exercise C	10.0K	+13889%	$38.08	$380.8K

Buy Sell Non-market (grant · exercise · gift)

About Hacker Severin

This profile aggregates every SEC Form 4 insider transaction reported by Hacker Severin across all companies they trade. Open-market purchases (code P) and sales (code S) are the highest-signal, discretionary trades; grants (A), option exercises (M) and gifts (G) reflect compensation rather than conviction and carry no market price. Figures cover the selected period and update as new filings are ingested.