Onto Innovation ONTO Insider Ownership

NYSE ONTO

$313.83 -11.55 (-3.55%)

At close: Oct 6, 2026 · 4:00 PM EDT

Insider Holdings by Owner

507.13K Shares

Insider Ownership Statistics

as of 30 Sep, 2026

Insider Ownership

0.772%

▼-0.022% pp QoQ

Shares Held by Insiders

381.68K

filed for Sep 2026

▼-2.75% QoQ

Shares Outstanding

49.41Mn

49,412,000 shares

Direct Holdings

381.68K

Indirect: 0

Net Shares Traded (QoQ)

-10.78K

net selling in Sep 2026

Insiders Holding Shares

with Form 4 holdings on file

Shares Owned by Insiders

Shares held % of outstanding

Latest —

Average ownership —

Peak ownership —

Shares Purchased/Sold by Insiders

Bought Sold

Latest quarter —

Net over range —

Buying quarters —

Insider Ownership Summary

Updated Oct 5, 2026

Over the trailing 12 months, ONTO insiders sold $902,300 worth of shares (3K shares) in open-market trades, with no open-market purchases.

Counted by insider, open-market selling of ONTO stock in the past 12 months came from 2 insiders, with no insider buying.
David Brian Miller (Director) led open-market sales of Onto Innovation stock over the past 12 months with $600,000 (2K shares), most recently on September 29, 2026.
Away from the open market, ONTO insiders received 34.39K shares in stock awards, acquired 27.5K shares through option exercises and conversions, gave up 34.39K shares to cover taxes or exercise prices and gave away 25K shares as gifts over the last 12 months.
Per Business Quant data, Onto Innovation insiders hold 381.68K shares in total based on their latest Form 4 filings, or 0.77% of the 49.41Mn shares outstanding; that total is down 2.75% from 392.46K shares at the end of Q2 2026 and down 15.86% from 453.6K shares at the end of Q3 2025.
Onto Innovation insiders report no indirect holdings: all 381.68K shares are held directly.
The insider holdings in Onto Innovation belong to 14 insiders who have reported on Form 4 within the past two years.
ONTO's three largest insider shareholders, per their latest Form 4 filings, are Michael P. Plisinski (Chief Executive Officer, 179.24K shares), Christopher A. Seams (Director, 38.51K shares) and Ido Dolev (EVP, Prod Solutions Group, 26.54K shares).
Of the shares held by ONTO insiders, 46.96% belong to Michael P. Plisinski.
In the past year, 12 insiders of Onto Innovation submitted 27 Form 4 filings reporting trades, awards or other transactions.
These insider figures for Onto Innovation are based on Form 4 filings through September 30, 2026.

Form 4 Holdings

Insiders Holding ONTO

Insiders 23

Shares held 507.13K

Of outstanding 1.03%

#	Insider	Position	Direct	Total	Share of Insiders	Last Filed
1	Michael P Plisinski	Chief Executive Officer	179,242	179,242	35.3%	04 Mar, 2026
2	Christine A Tsingos	Director	42,918	42,918	8.5%	23 May, 2024
3	Christopher A Seams	Director	38,513	38,513	7.6%	22 May, 2026
4	Ido Dolev	Evp, Prod Solutions Grp	26,536	26,536	5.2%	04 Mar, 2026
5	Steven R Roth	Sr Vp Cfo	23,043	23,043	4.5%	13 Feb, 2022
6	Yoon Ah Oh	Svp, Gen Counsel Corp Sec	21,110	21,110	4.2%	18 May, 2026
7	Brian K Roberts	Chief Financial Officer	21,032	21,032	4.1%	04 Sep, 2026
8	Leo Berlinghieri	Director	20,210	20,210	4.0%	23 May, 2024
9	Srinivas Vedula	Svp, Customer Success	18,730	18,730	3.7%	05 Mar, 2025
10	Ramil Yaldaei	Chief Operating Officer	17,593	17,593	3.5%	18 May, 2026
11	Shirley Chen	Senior Vice President Of Custo	14,001	14,001	2.8%	04 Sep, 2026
12	Mark Slicer	Chief Financial Officer	13,640	13,640	2.7%	19 May, 2025
13	David Brian Miller	Director	10,692	10,692	2.1%	30 Sep, 2026
14	Ju Jin	Svp Gm, Ibu	10,254	10,254	2.0%	16 Jun, 2023
15	Robert Fiordalice	Svp Gm, Metrology Bu	8,763	8,763	1.7%	05 Mar, 2024
16	James Harlow	Chief Operating Officer	8,586	8,586	1.7%	15 Feb, 2023
17	May Su	Director	7,984	7,984	1.6%	22 May, 2026
18	Stephen Douglas Kelley	Director	6,384	6,384	1.3%	22 May, 2026
19	Karen M Rogge	Director	5,150	5,150	1.0%	11 May, 2023
20	Stephen S Schwartz	Director	3,536	3,536	0.7%	22 May, 2026
21	Bruce C Rhine	Director	3,500	3,500	0.7%	17 Feb, 2022
22	D Mayson Brooks	Vice President Gm, Ibu	3,025	3,025	0.6%	04 Sep, 2024
23	Susan D Lynch	Director	2,684	2,684	0.5%	25 Aug, 2026

Each row is that insider’s most recently reported position, from Form 4 filings over the last 60 months — which is why this total does not tie to the quarterly series above, where a quarter counts only the insiders who filed in it. Shares held through a fund or institutional portfolio are counted on the institutional ownership page instead.

Form 4 Filings

1,992 Insider Transactions

Source SEC Form 4

Latest quarter Sep 2026

Date	Insider	Position	Transaction	Shares	Price	Value	Shares Held After	Ownership
29 Sep, 2026	David Brian Miller	Director	Disposed S	2,000	$300.00	$600.00K	10,692	Direct
02 Sep, 2026	Shirley Chen	Senior Vice President Of Custo	Disposed F	1,516	$254.55	$385.90K	14,001	Direct
02 Sep, 2026	Brian K Roberts	Chief Financial Officer	Disposed F	3,239	$254.55	$824.49K	21,032	Direct
02 Sep, 2026	Brian K Roberts	Chief Financial Officer	Disposed F	3,239	$254.55	$824.49K	21,032	Direct
21 Aug, 2026	Susan D Lynch	Director	Disposed S	1,000	$302.30	$302.30K	2,684	Direct
20 May, 2026	David Brian Miller	Director	Acquired A	761	$0.00	$0	12,692	Direct
20 May, 2026	Stephen Douglas Kelley	Director	Acquired A	761	$0.00	$0	6,384	Direct
20 May, 2026	Christopher A Seams	Director	Acquired A	761	$0.00	$0	38,513	Direct
20 May, 2026	Stephen S Schwartz	Director	Acquired A	761	$0.00	$0	3,536	Direct
20 May, 2026	Susan D Lynch	Director	Acquired A	761	$0.00	$0	3,684	Direct
20 May, 2026	May Su	Director	Acquired A	761	$0.00	$0	7,984	Direct
15 May, 2026	Yoon Ah Oh	Svp, Gen Counsel Corp Sec	Disposed F	530	$271.77	$144.04K	21,110	Direct
15 May, 2026	Ramil Yaldaei	Chief Operating Officer	Disposed F	218	$271.77	$59.25K	18,218	Direct
15 May, 2026	Ramil Yaldaei	Chief Operating Officer	Disposed F	625	$271.77	$169.86K	17,593	Direct
02 Mar, 2026	Ramil Yaldaei	Chief Operating Officer	Acquired A	7,683	$0.00	$0	19,051	Direct
02 Mar, 2026	Ido Dolev	Evp, Prod Solutions Grp	Acquired A	3,440	$0.00	$0	27,355	Direct
02 Mar, 2026	Brian K Roberts	Chief Financial Officer	Acquired A	3,096	$0.00	$0	24,271	Direct
02 Mar, 2026	Michael P Plisinski	Chief Executive Officer	Acquired A	14,479	$0.00	$0	182,984	Direct
02 Mar, 2026	Yoon Ah Oh	Svp, Gen Counsel Corp Sec	Acquired A	2,408	$0.00	$0	22,057	Direct
02 Mar, 2026	Shirley Chen	Svp Customer Success	Acquired A	2,523	$0.00	$0	15,517	Direct

Showing 1 to 20 of 1,992 transactions