Zenas BioPharma, Inc. Insider Trading

ZBIO

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Last 12 months

Insiders bought $11.4M on the open market and sold nothing.

Net open-market

+$11.4M

10 buys · 0 sales

Under a 10b5-1 plan

—

no sales

Insiders who bought / sold

4 / 0

executives and directors

Last open-market buy

May 2026

May 18, 2026

Get an email when ZBIO's executives or directors buy, or make a large sale outside a plan.

Trades · last 2 years

Date	Insider	Trade	Shares	Price	Value	Of their stake	Filing
May 18	Leon O Moulder Jr Chief Executive Officer	Bought	60,000	$16.88	$1.01M	13%	Form 4
Apr 28 – 29	Leon O Moulder Jr Chief Executive Officer	Bought 2 parts	60,000	$17.79 average	$1.07M	2.8%	Form 4
Mar 31	Hongbo Lu Director	Bought	3,768	$18.63	70K	0.9%	Form 4
Mar 31	Tomas Kiselak Director	Bought	150,000	$20.00	$3M	6.8%	Form 4
Mar 30 – 31	Leon O Moulder Jr Chief Executive Officer	Bought 2 parts	54,000	$18.91 average	$1.02M	2.6%	Form 4
Mar 31	Hongbo Lu Director	Bought	75,000	$20.00	$1.5M	22%	Form 4
Feb 12 – 13	Patricia L Allen Director	Bought 4 parts	19,860	$25.16 average	500K	New	Form 4
Feb 11	Hongbo Lu Director	Bought	25,985	$22.50	585K	8.1%	Form 4
Feb 2	Leon O Moulder Jr Chief Executive Officer	Bought	57,000	$17.96	$1.02M	14%	Form 4
Jan 7 – 9	Leon O Moulder Jr Chief Executive Officer	Bought 3 parts	100,000	$16.39 average	$1.64M	5.2%	Form 4
Oct 9, 2025	Jason Raleigh Nunn Director	Bought	63,158	$19.00	$1.2M	2.1%	Form 4
Oct 9, 2025	SR ONE Capital Management, LLC Large holder	Bought 2 parts	126,315	$19.00 average	$2.4M	2.6%	Form 4
Oct 9, 2025	Patrick G Enright Director	Bought 2 parts	117,255	$19.19 average	$2.25M	6.8%	Form 4
Oct 7, 2025	Leon O Moulder Jr See Remarks	Bought	36,928	$20.85	770K	14%	Form 4
Oct 7, 2025	Peter Evan Harwin Director	Bought	316,219	$19.00	$6.01M	17%	Form 4
Oct 7, 2025	Hongbo Lu Director	Bought	263,160	$19.00	$5M	447%	Form 4
Feb 18, 2025	Leon O Moulder Jr Chief Executive Officer	Bought	25,000	$6.67	167K	1.3%	Form 4
Feb 7, 2025	Ting Xiao Director	Bought	10,000	$7.76	78K	New	Form 4
Dec 3, 2024 – Dec 4, 2024	Leon O Moulder Jr Chief Executive Officer	Bought 2 parts	70,000	$10.26 average	718K	3.8%	Form 4
Nov 18, 2024 – Nov 19, 2024	Leon O Moulder Jr Chief Executive Officer	Bought 2 parts	10,000	$14.89 average	149K	0.5%	Form 4

May 18
Leon O Moulder Jr
Chief Executive Officer · bought 60,000 at $16.88
$1.01M
13% of stake
Apr 28 – 29
Leon O Moulder Jr
Chief Executive Officer · bought 60,000 at avg $17.79
$1.07M
2.8% of stake
Mar 31
Hongbo Lu
Director · bought 3,768 at $18.63
70K
0.9% of stake
Mar 31
Tomas Kiselak
Director · bought 150,000 at $20.00
$3M
6.8% of stake
Mar 30 – 31
Leon O Moulder Jr
Chief Executive Officer · bought 54,000 at avg $18.91
$1.02M
2.6% of stake
Mar 31
Hongbo Lu
Director · bought 75,000 at $20.00
$1.5M
22% of stake
Feb 12 – 13
Patricia L Allen
Director · bought 19,860 at avg $25.16
500K
New position
Feb 11
Hongbo Lu
Director · bought 25,985 at $22.50
585K
8.1% of stake
Feb 2
Leon O Moulder Jr
Chief Executive Officer · bought 57,000 at $17.96
$1.02M
14% of stake
Jan 7 – 9
Leon O Moulder Jr
Chief Executive Officer · bought 100,000 at avg $16.39
$1.64M
5.2% of stake
Oct 9, 2025
Jason Raleigh Nunn
Director · bought 63,158 at $19.00
$1.2M
2.1% of stake
Oct 9, 2025
SR ONE Capital Management, LLC
Large holder · bought 126,315 at avg $19.00
$2.4M
2.6% of stake
Oct 9, 2025
Patrick G Enright
Director · bought 117,255 at avg $19.19
$2.25M
6.8% of stake
Oct 7, 2025
Leon O Moulder Jr
See Remarks · bought 36,928 at $20.85
770K
14% of stake
Oct 7, 2025
Peter Evan Harwin
Director · bought 316,219 at $19.00
$6.01M
17% of stake
Oct 7, 2025
Hongbo Lu
Director · bought 263,160 at $19.00
$5M
447% of stake
Feb 18, 2025
Leon O Moulder Jr
Chief Executive Officer · bought 25,000 at $6.67
167K
1.3% of stake
Feb 7, 2025
Ting Xiao
Director · bought 10,000 at $7.76
78K
New position
Dec 3, 2024 – Dec 4, 2024
Leon O Moulder Jr
Chief Executive Officer · bought 70,000 at avg $10.26
718K
3.8% of stake
Nov 18, 2024 – Nov 19, 2024
Leon O Moulder Jr
Chief Executive Officer · bought 10,000 at avg $14.89
149K
0.5% of stake

How to read this. Insiders sell for many reasons: taxes, diversifying, a house. Open-market buys are rarer and say more. A 10b5-1 plan is a trading schedule set up months in advance, so those sales were not timed on news. Large holders (funds and 10% owners) are listed under Everything but not counted as insiders. If you own or watch ZBIO, we send a push when an executive buys or makes a large sale outside a plan.

Source: SEC Form 4 filings, filed within two business days of each trade and checked for new ones every hour.

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Held by ETFs

ZBIO is in 37 US ETFs. The largest of them, with ZBIO's weight in each:

Spot a number that looks wrong? Check it in ZBIO's SEC filings or

Download this analysis as a PDF (Pro)

Data sourced from SEC EDGAR filings and third-party price providers. Scores, valuations, and metrics are algorithmic estimates. This is not investment advice. See our Terms and Methodology.

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