LEFF JONATHAN S

Director at Altus Pharmaceuticals Inc. · on record since Jan 25, 2006
Director at Viracta Therapeutics, Inc. · on record since Mar 22, 2006
10% owner at Viracta Therapeutics, Inc. · on record since Mar 22, 2006
Director at NEUROGEN CORP · on record since Mar 16, 2006
10% owner at Altus Pharmaceuticals Inc. · on record since Feb 2, 2006
Director at INTERMUNE INC · on record since May 25, 2006
Director at ALLOS THERAPEUTICS INC · on record since May 16, 2006
Director at ZYMOGENETICS INC · on record since Jun 16, 2006
Director at Tessera Defense & Homeland Security Inc. · on record since Mar 21, 2024
Director at INSPIRE PHARMACEUTICALS INC · on record since Jul 23, 2007
Director at Talon Therapeutics, Inc. · on record since Jun 16, 2010
10% owner at ZYMOGENETICS INC · on record since Oct 12, 2010
Director at Larimar Therapeutics, Inc. · on record since May 20, 2026
Director at ALPINE IMMUNE SCIENCES, INC. · on record since Jun 16, 2015
Director at AveXis, Inc. · on record since Feb 12, 2016
Director at Protara Therapeutics, Inc. · on record since Aug 4, 2017
Director at SPYR, Inc. · on record since Nov 10, 2022

Insider trading activity of LEFF JONATHAN S

Transactions on record: 391; since Nov 26, 2003

Open-market buys: 267; $176.6M

Open-market sells: 0

Companies traded: 13; last filing May 20, 2026

Figures computed from official regulatory filings — .

Companies where LEFF JONATHAN S has traded

7 tx · May 20, 2026
3 tx · Apr 21, 2025
2 tx · Jun 12, 2018
2 tx · Feb 12, 2016
2 tx · Sep 15, 2015
52 tx · $96.4M · Mar 1, 2013
14 tx · $20.6M · Sep 5, 2012
6 tx · $9.9M · Feb 22, 2012
13 tx · $154.5M · May 16, 2011
246 tx · $101.2M · Oct 12, 2010
25 tx · Jul 28, 2008
7 tx · $7M · Jun 13, 2008
12 tx · $11.1M · Jun 5, 2008

Track record of LEFF JONATHAN S

Open-market buys: 270

Last buy: Jan 26, 2010

Enough buys on record, but none of them has a 63-day return yet — this happens when the shares stopped trading, or when the buys are too recent. Win rates will appear once returns mature.

Transaction history of LEFF JONATHAN S

Co-insiders of LEFF JONATHAN S

This page republishes public regulatory disclosures.

Company	Filed	Type	Qty	Price	Value · USD	Signals	Src
Larimar Therapeutics, Inc.Listing on record	May 20, 2026	AwardD (derivative)	55,150	0.00 USD	n/a (Non-cash transaction: the filing states a price of zero (award, gift, exercise))		SEC
Larimar Therapeutics, Inc.Listing on record	May 14, 2025	AwardD (derivative)	19,000	0.00 USD	n/a (Non-cash transaction: the filing states a price of zero (award, gift, exercise))		SEC
Tessera Defense & Homeland Security Inc.Listing on record	Apr 21, 2025	AwardD (derivative)	17,600	0.00 USD	n/a (Non-cash transaction: the filing states a price of zero (award, gift, exercise))		SEC
Tessera Defense & Homeland Security Inc.Listing on record	Apr 18, 2025	AwardD (derivative)	-17,600	0.00 USD	n/a (Non-cash transaction: the filing states a price of zero (award, gift, exercise))		SEC
Tessera Defense & Homeland Security Inc.Listing on record	Jul 15, 2024	AwardD (derivative)	264,000	0.00 USD	n/a (Non-cash transaction: the filing states a price of zero (award, gift, exercise))		SEC
Larimar Therapeutics, Inc.Listing on record	May 31, 2024	AwardD (derivative)	19,000	0.00 USD	n/a (Non-cash transaction: the filing states a price of zero (award, gift, exercise))		SEC
Larimar Therapeutics, Inc.Listing on record	May 11, 2023	AwardD (derivative)	8,300	0.00 USD	n/a (Non-cash transaction: the filing states a price of zero (award, gift, exercise))		SEC
Larimar Therapeutics, Inc.Listing on record	May 12, 2022	AwardD (derivative)	8,300	0.00 USD	n/a (Non-cash transaction: the filing states a price of zero (award, gift, exercise))		SEC
Larimar Therapeutics, Inc.Listing on record	May 17, 2021	AwardD (derivative)	8,300	0.00 USD	n/a (Non-cash transaction: the filing states a price of zero (award, gift, exercise))		SEC
Larimar Therapeutics, Inc.Listing on record	Sep 30, 2020	AwardD (derivative)	16,600	0.00 USD	n/a (Non-cash transaction: the filing states a price of zero (award, gift, exercise))		SEC
Protara Therapeutics, Inc.Listing on record	Jun 12, 2018	AwardD (derivative)	12,700	0.00 USD	n/a (Non-cash transaction: the filing states a price of zero (award, gift, exercise))		SEC
Protara Therapeutics, Inc.Listing on record	Aug 4, 2017	AwardD (derivative)	13,333	0.00 USD	n/a (Non-cash transaction: the filing states a price of zero (award, gift, exercise))		SEC
AveXis, Inc.Listing unverified	Feb 12, 2016	AwardD (derivative)	8,385	0.00 USD	n/a (Non-cash transaction: the filing states a price of zero (award, gift, exercise))		SEC
AveXis, Inc.Listing unverified	Feb 12, 2016	AwardD (derivative)	18,111	0.00 USD	n/a (Non-cash transaction: the filing states a price of zero (award, gift, exercise))		SEC
ALPINE IMMUNE SCIENCES, INC.Listing unverified	Sep 15, 2015	AwardD (derivative)	7,650	0.00 USD	n/a (Non-cash transaction: the filing states a price of zero (award, gift, exercise))		SEC
ALPINE IMMUNE SCIENCES, INC.Listing unverified	Jul 20, 2015	AwardD (derivative)	11,475	—	n/a (No price was disclosed in the filing)		SEC
INTERMUNE INCListing unverified	Mar 1, 2013	Other	-7,108	8.79 USD	$62.5K		SEC
ALLOS THERAPEUTICS INCListing unverified	Sep 5, 2012	Other	-55,000	1.82 USD	$100.1K		SEC
INTERMUNE INCListing unverified	Jun 6, 2012	Award	2,500	10.10 USD	$25.3K		SEC
INTERMUNE INCListing unverified	Jun 6, 2012	AwardD (derivative)	6,000	0.00 USD	n/a (Non-cash transaction: the filing states a price of zero (award, gift, exercise))		SEC
Talon Therapeutics, Inc.Listing unverified	Feb 22, 2012	AwardD (derivative)	35,000	0.00 USD	n/a (Non-cash transaction: the filing states a price of zero (award, gift, exercise))		SEC
Talon Therapeutics, Inc.Listing unverified	Jan 10, 2012	AwardD (derivative)	1	—	n/a (No price was disclosed in the filing)		SEC
Talon Therapeutics, Inc.Listing unverified	Jan 10, 2012	AwardD (derivative)	99,000	100.00 USD	$9.9M	Unusual size	SEC
ALLOS THERAPEUTICS INCListing unverified	Dec 15, 2011	Award	55,000	0.00 USD	n/a (Non-cash transaction: the filing states a price of zero (award, gift, exercise))		SEC
ALLOS THERAPEUTICS INCListing unverified	Jun 23, 2011	AwardD (derivative)	20,000	2.06 USD	$41.2K		SEC

Company	Filed	Type	Qty	Price	Value · USD	Signals	Src
Larimar Therapeutics, Inc.Listing on record	May 20, 2026	AwardD (derivative)	55,150	0.00 USD	n/a (Non-cash transaction: the filing states a price of zero (award, gift, exercise))		SEC
Larimar Therapeutics, Inc.Listing on record	May 14, 2025	AwardD (derivative)	19,000	0.00 USD	n/a (Non-cash transaction: the filing states a price of zero (award, gift, exercise))		SEC
Tessera Defense & Homeland Security Inc.Listing on record	Apr 21, 2025	AwardD (derivative)	17,600	0.00 USD	n/a (Non-cash transaction: the filing states a price of zero (award, gift, exercise))		SEC
Tessera Defense & Homeland Security Inc.Listing on record	Apr 18, 2025	AwardD (derivative)	-17,600	0.00 USD	n/a (Non-cash transaction: the filing states a price of zero (award, gift, exercise))		SEC
Tessera Defense & Homeland Security Inc.Listing on record	Jul 15, 2024	AwardD (derivative)	264,000	0.00 USD	n/a (Non-cash transaction: the filing states a price of zero (award, gift, exercise))		SEC
Larimar Therapeutics, Inc.Listing on record	May 31, 2024	AwardD (derivative)	19,000	0.00 USD	n/a (Non-cash transaction: the filing states a price of zero (award, gift, exercise))		SEC
Larimar Therapeutics, Inc.Listing on record	May 11, 2023	AwardD (derivative)	8,300	0.00 USD	n/a (Non-cash transaction: the filing states a price of zero (award, gift, exercise))		SEC
Larimar Therapeutics, Inc.Listing on record	May 12, 2022	AwardD (derivative)	8,300	0.00 USD	n/a (Non-cash transaction: the filing states a price of zero (award, gift, exercise))		SEC
Larimar Therapeutics, Inc.Listing on record	May 17, 2021	AwardD (derivative)	8,300	0.00 USD	n/a (Non-cash transaction: the filing states a price of zero (award, gift, exercise))		SEC
Larimar Therapeutics, Inc.Listing on record	Sep 30, 2020	AwardD (derivative)	16,600	0.00 USD	n/a (Non-cash transaction: the filing states a price of zero (award, gift, exercise))		SEC
Protara Therapeutics, Inc.Listing on record	Jun 12, 2018	AwardD (derivative)	12,700	0.00 USD	n/a (Non-cash transaction: the filing states a price of zero (award, gift, exercise))		SEC
Protara Therapeutics, Inc.Listing on record	Aug 4, 2017	AwardD (derivative)	13,333	0.00 USD	n/a (Non-cash transaction: the filing states a price of zero (award, gift, exercise))		SEC
AveXis, Inc.Listing unverified	Feb 12, 2016	AwardD (derivative)	8,385	0.00 USD	n/a (Non-cash transaction: the filing states a price of zero (award, gift, exercise))		SEC
AveXis, Inc.Listing unverified	Feb 12, 2016	AwardD (derivative)	18,111	0.00 USD	n/a (Non-cash transaction: the filing states a price of zero (award, gift, exercise))		SEC
ALPINE IMMUNE SCIENCES, INC.Listing unverified	Sep 15, 2015	AwardD (derivative)	7,650	0.00 USD	n/a (Non-cash transaction: the filing states a price of zero (award, gift, exercise))		SEC
ALPINE IMMUNE SCIENCES, INC.Listing unverified	Jul 20, 2015	AwardD (derivative)	11,475	—	n/a (No price was disclosed in the filing)		SEC
INTERMUNE INCListing unverified	Mar 1, 2013	Other	-7,108	8.79 USD	$62.5K		SEC
ALLOS THERAPEUTICS INCListing unverified	Sep 5, 2012	Other	-55,000	1.82 USD	$100.1K		SEC
INTERMUNE INCListing unverified	Jun 6, 2012	Award	2,500	10.10 USD	$25.3K		SEC
INTERMUNE INCListing unverified	Jun 6, 2012	AwardD (derivative)	6,000	0.00 USD	n/a (Non-cash transaction: the filing states a price of zero (award, gift, exercise))		SEC
Talon Therapeutics, Inc.Listing unverified	Feb 22, 2012	AwardD (derivative)	35,000	0.00 USD	n/a (Non-cash transaction: the filing states a price of zero (award, gift, exercise))		SEC
Talon Therapeutics, Inc.Listing unverified	Jan 10, 2012	AwardD (derivative)	1	—	n/a (No price was disclosed in the filing)		SEC
Talon Therapeutics, Inc.Listing unverified	Jan 10, 2012	AwardD (derivative)	99,000	100.00 USD	$9.9M	Unusual size	SEC
ALLOS THERAPEUTICS INCListing unverified	Dec 15, 2011	Award	55,000	0.00 USD	n/a (Non-cash transaction: the filing states a price of zero (award, gift, exercise))		SEC
ALLOS THERAPEUTICS INCListing unverified	Jun 23, 2011	AwardD (derivative)	20,000	2.06 USD	$41.2K		SEC