SHC insider ownership: who sold, why, and what they still hold

What stands out

Two officers sold $36.3M with no disclosed plan: Michael Petras Jr. ($33.5M) and Michael Rutz ($2.8M). The filings don't state a reason.Michael Petras Jr.: largest such sale, Aug 17, 2026 · Michael Rutz: largest such sale, Aug 7, 2026

Outside holders and shareholders represented on the board, not part of management, sold heavily: WARBURG PINCUS & CO. ($1.92B) and GTCR INVESTMENT XI LLC ($639M).WARBURG PINCUS & CO.: largest sale, May 13, 2026 · GTCR INVESTMENT XI LLC: largest sale, May 13, 2026

Selling picked up in the last 90 days: officers and directors sold 1.29M shares, against an average of 245K per 90 days earlier in the period. Most of it was Michael Petras Jr. (1.14M shares in the last 90 days) and Michael Rutz (150K shares in the last 90 days); 0% of these sales were under disclosed plans.Michael Petras Jr.: largest recent sale, Aug 17, 2026 · Michael Rutz: largest recent sale, Aug 7, 2026

A share of stake is shown for 0 of the 2 officers and directors who sold. 18 are left out

Left out: Michael Petras Jr., Michael Rutz, Alexander Dimitrief, Jonathan Lyons, Ann Klee, Constantine Mihas, Sean Cunningham, Ruoxi Chen, James Neary, Vincent Petrella, David Wheadon, Erika Ostrowski, Robert Knauss, Karen Flynn, Christopher Simon, Richard Kyle, Kenneth Krause and Alton Shader (share of stake is being verified).

Disclosed company stock is not an insider's whole wealth.

Who sold, and how much of their stake

Officers and directors, past 12 months. Their share of stake is being verified and is not shown yet; amounts and trading plans are below.

Michael Petras Jr.

Executive Chairman, Director

Not confirmed

Share of stake not shown: share of stake is being verified. Why

$33.5MNo plan disclosed

Michael Rutz

President of Sterigenics

Not confirmed

Share of stake not shown: share of stake is being verified. Why

$2.8MNo plan disclosed

Amounts, filings and trading plans for each seller

Selling by month

Officers and directors, Oct 2025 to Oct 2026. Each sale is counted once: under a disclosed plan, else to cover taxes, else no plan disclosed.

No plan disclosedOne dollar scale for every month; the tallest bar is labeled

Recent activity

Past 30 days, Sep 14, 2026 to Oct 13, 2026

No officer or director trades were reported for the past 30 days. The most recent before that:

Aug 17, 2026Michael Petras Jr. sold 1.14M shares ($21.2M) with no plan disclosed.

Who	Shares	Price	% of total stake	Total stake after	Trade date	Filed
Michael Petras Jr. Executive Chairman, Director	1,144,515	$18.50	n/a	n/a	Aug 17, 2026	Aug 19, 2026

Outside holders, reported separately

WARBURG PINCUS & CO. sold $1.92B and GTCR INVESTMENT XI LLC sold $639M in the past 12 months. Large shareholders and the funds or companies that board members represent are not part of management, so they are left out of the figures above.

Details

Common questions

Is the Sotera Health Co CEO selling stock?

No. Alton Shader reported no open-market sales in the past 12 months.

Why are Sotera Health Co insiders selling?

Filings rarely give a reason, and we don't guess at one. What they show is how the sales were made: 0% of sales by value ran under 10b5-1 trading plans disclosed in the filings and 100% had no disclosed plan. A trading plan schedules sales in advance.

Are any Sotera Health Co insiders buying?

No. Officers and directors reported no purchases in the past 12 months.

The evidence

Who sold2 officers and directors: amount, % of holdings, trading plan

Who sold	Amount	% of holdings	Trading plan
Michael Petras Jr. Executive Chairman, Director	$33.5M 1.89M shares	Not confirmed share of stake is being verified. Why	No plan disclosed
Michael Rutz President of Sterigenics	$2.8M 150K shares	Not confirmed share of stake is being verified. Why	No plan disclosed

Outside holder, reported separately: WARBURG PINCUS & CO. (a 10% owner, not part of management). Sold $1.92B (123.65M shares) from Nov 10, 2025 to May 13, 2026. Latest filing

Outside holder, reported separately: GTCR INVESTMENT XI LLC (a 10% owner, not part of management). Sold $639M (41.22M shares) from Nov 10, 2025 to May 13, 2026. Latest filing

The full ownership picture0 of 18 officers and directors confirmed

Vested shares across all share classes, held directly and through trusts, LLCs and family members, as reported on SEC Forms 3, 4 and 5. Unvested awards and options are never counted as owned shares.

Insider

Held Oct 13, 2025

Sold

Held Oct 13, 2026

Still held

Michael Petras Jr.

Holdings and share of stake are being verified. Share-of-stake figures and holdings for this company are held back while they are verified. See the filing Sales and other transactions for Michael Petras Jr. are complete.

Executive Chairman, Director

n/a

−1.89M

n/a

Vesting, gifts, unvested awards and holding lines for Michael Petras Jr.

Holdings and share of stake are being verified. Sales, proceeds, plan and tax status and dates for Michael Petras Jr. are complete; balances and unit counts will be added when the check is finished.

0gifted (net of own trusts)

−190Kwithheld by the company for taxes

Stock options (not counted as shares):

Options held	Strike price	Expires	Intrinsic value (estimate)
1,118,012	$23.00	Nov 20, 2030	$0
478,932	$20.03	Mar 2, 2032	$0
2,108,356	$6.37	Nov 7, 2032	$25.6M
404,094	$17.59	Mar 6, 2033	$368K
544,509	$14.59	Mar 4, 2034	$2.1M

Estimate: options held × ($18.50 − strike price), using the most recent insider trade price on Form 4 (Aug 17, 2026), not a market close.

Michael Rutz

President of Sterigenics

n/a

−150K

n/a

Vesting, gifts, unvested awards and holding lines for Michael Rutz

Holdings and share of stake are being verified. Sales, proceeds, plan and tax status and dates for Michael Rutz are complete; balances and unit counts will be added when the check is finished.

0gifted (net of own trusts)

−26Kwithheld by the company for taxes

Stock options (not counted as shares):

Options held	Strike price	Expires	Intrinsic value (estimate)
111,801	$23.00	Nov 20, 2030	$0
63,857	$20.03	Mar 2, 2032	$0
53,879	$17.59	Mar 6, 2033	$49K
68,063	$14.59	Mar 4, 2034	$266K

Estimate: options held × ($18.50 − strike price), using the most recent insider trade price on Form 4 (Aug 17, 2026), not a market close.

Alexander Dimitrief

Former SVP, GC and Sec.

n/a

Vesting, gifts, unvested awards and holding lines for Alexander Dimitrief

Holdings and share of stake are being verified. Sales, proceeds, plan and tax status and dates for Alexander Dimitrief are complete; balances and unit counts will be added when the check is finished.

0gifted (net of own trusts)

−40Kwithheld by the company for taxes

Stock options (not counted as shares):

Options held	Strike price	Expires	Intrinsic value (estimate)
602,387	$6.37	Nov 7, 2032	$7.3M
102,095	$14.59	Mar 4, 2034	$399K

Estimate: options held × ($18.50 − strike price), using the most recent insider trade price on Form 4 (Aug 17, 2026), not a market close.

Jonathan Lyons

Sr. Vice President, CFO

n/a

Vesting, gifts, unvested awards and holding lines for Jonathan Lyons

Holdings and share of stake are being verified. Sales, proceeds, plan and tax status and dates for Jonathan Lyons are complete; balances and unit counts will be added when the check is finished.

0gifted (net of own trusts)

−50Kwithheld by the company for taxes

Stock options (not counted as shares):

Options held	Strike price	Expires	Intrinsic value (estimate)
33,640	$16.89	Aug 7, 2033	$54K
81,676	$14.59	Mar 4, 2034	$319K

Estimate: options held × ($18.50 − strike price), using the most recent insider trade price on Form 4 (Aug 17, 2026), not a market close.

Ann Klee

Holdings and share of stake are being verified. Share-of-stake figures and holdings for this company are held back while they are verified. Sales and other transactions for Ann Klee are complete.

Director

n/a

Vesting, gifts, unvested awards and holding lines for Ann Klee

Holdings and share of stake are being verified. Sales, proceeds, plan and tax status and dates for Ann Klee are complete; balances and unit counts will be added when the check is finished.

0gifted (net of own trusts)

Constantine Mihas

Holdings and share of stake are being verified. Share-of-stake figures and holdings for this company are held back while they are verified. Sales and other transactions for Constantine Mihas are complete.

Director

n/a

Vesting, gifts, unvested awards and holding lines for Constantine Mihas

Holdings and share of stake are being verified. Sales, proceeds, plan and tax status and dates for Constantine Mihas are complete; balances and unit counts will be added when the check is finished.

0gifted (net of own trusts)

Sean Cunningham

Director

n/a

Vesting, gifts, unvested awards and holding lines for Sean Cunningham

Holdings and share of stake are being verified. Sales, proceeds, plan and tax status and dates for Sean Cunningham are complete; balances and unit counts will be added when the check is finished.

0gifted (net of own trusts)

Ruoxi Chen

Director

n/a

Vesting, gifts, unvested awards and holding lines for Ruoxi Chen

Holdings and share of stake are being verified. Sales, proceeds, plan and tax status and dates for Ruoxi Chen are complete; balances and unit counts will be added when the check is finished.

0gifted (net of own trusts)

James Neary

Director

n/a

Vesting, gifts, unvested awards and holding lines for James Neary

Holdings and share of stake are being verified. Sales, proceeds, plan and tax status and dates for James Neary are complete; balances and unit counts will be added when the check is finished.

0gifted (net of own trusts)

Vincent Petrella

Director

n/a

Vesting, gifts, unvested awards and holding lines for Vincent Petrella

Holdings and share of stake are being verified. Sales, proceeds, plan and tax status and dates for Vincent Petrella are complete; balances and unit counts will be added when the check is finished.

0gifted (net of own trusts)

David Wheadon

Director

n/a

Vesting, gifts, unvested awards and holding lines for David Wheadon

Holdings and share of stake are being verified. Sales, proceeds, plan and tax status and dates for David Wheadon are complete; balances and unit counts will be added when the check is finished.

0gifted (net of own trusts)

Erika Ostrowski

SVP, General Counsel and Sec.

n/a

Vesting, gifts, unvested awards and holding lines for Erika Ostrowski

Holdings and share of stake are being verified. Sales, proceeds, plan and tax status and dates for Erika Ostrowski are complete; balances and unit counts will be added when the check is finished.

0gifted (net of own trusts)

Stock options (not counted as shares):

Options held	Strike price	Expires	Intrinsic value (estimate)
20,419	$14.59	n/a	$80K
11,740	$14.59	n/a	$46K

Estimate: options held × ($18.50 − strike price), using the most recent insider trade price on Form 4 (Aug 17, 2026), not a market close.

Robert Knauss

Director

n/a

Vesting, gifts, unvested awards and holding lines for Robert Knauss

Holdings and share of stake are being verified. Sales, proceeds, plan and tax status and dates for Robert Knauss are complete; balances and unit counts will be added when the check is finished.

0gifted (net of own trusts)

Karen Flynn

Director

n/a

Vesting, gifts, unvested awards and holding lines for Karen Flynn

Holdings and share of stake are being verified. Sales, proceeds, plan and tax status and dates for Karen Flynn are complete; balances and unit counts will be added when the check is finished.

0gifted (net of own trusts)

Christopher Simon

Director

n/a

Vesting, gifts, unvested awards and holding lines for Christopher Simon

Holdings and share of stake are being verified. Sales, proceeds, plan and tax status and dates for Christopher Simon are complete; balances and unit counts will be added when the check is finished.

0gifted (net of own trusts)

Richard Kyle

Director

n/a

Vesting, gifts, unvested awards and holding lines for Richard Kyle

Holdings and share of stake are being verified. Sales, proceeds, plan and tax status and dates for Richard Kyle are complete; balances and unit counts will be added when the check is finished.

0gifted (net of own trusts)

Kenneth Krause

Director

n/a

Vesting, gifts, unvested awards and holding lines for Kenneth Krause

Holdings and share of stake are being verified. Sales, proceeds, plan and tax status and dates for Kenneth Krause are complete; balances and unit counts will be added when the check is finished.

0gifted (net of own trusts)

Alton Shader

Chief Executive Officer, Director

n/a

Vesting, gifts, unvested awards and holding lines for Alton Shader

Holdings and share of stake are being verified. Sales, proceeds, plan and tax status and dates for Alton Shader are complete; balances and unit counts will be added when the check is finished.

0gifted (net of own trusts)

Holdings and share of stake for Sotera Health Co are being verified, so no balances, unit counts or percentages are shown. Sales, proceeds, plan and tax status, titles and dates come straight from individual filings.

What explains the selling$36.3M of sales by plan status, purpose, seller and month

Officer and director open-market sales: $36.3M across 2,044,515 shares. Plan status and stated purpose are separate questions, and a sale can have both.

By plan status

No plan disclosed · $36.3M

Sales with no 10b5-1 plan and no tax reference in the filing. $33.5M of it is Michael Petras Jr.. No plan disclosed is a statement about the filing, not about why the sale happened. Largest such sale: Michael Petras Jr., Aug 17, 2026

Taxes

305,109 shares ($4.9M) were withheld by the company for taxes, which isn't a market sale.

Seller	Shares sold	Proceeds	Under a disclosed plan	Share of total	Sales dates
Michael Petras Jr. Executive Chairman, Director	1.89M	$33.5M	0%	92%	Dec 8, 2025 to Aug 17, 2026
Michael Rutz President of Sterigenics	150K	$2.8M	0%	8%	Aug 7, 2026 to Aug 7, 2026

Sales by month

Month	Sale proceeds	Disclosed plan	To cover taxes	No plan disclosed
Oct 2025	$0	$0	$0	$0
Nov 2025	$0	$0	$0	$0
Dec 2025	$12.3M	$0	$0	$12.3M
Jan 2026	$0	$0	$0	$0
Feb 2026	$0	$0	$0	$0
Mar 2026	$0	$0	$0	$0
Apr 2026	$0	$0	$0	$0
May 2026	$0	$0	$0	$0
Jun 2026	$0	$0	$0	$0
Jul 2026	$0	$0	$0	$0
Aug 2026	$24.0M	$0	$0	$24.0M
Sep 2026	$0	$0	$0	$0
Oct 2026	$0	$0	$0	$0

Is this normal? Selling year by year4 earlier years to compare with

More than usual: $36.3M sold, after almost none in the past 4 years. 2 insiders sold; the average is 1 a year.

12 months ending	Shares sold	Insiders who sold	Proceeds
Oct 13, 2026 Latest 12 months	2.04M	2	$36.3M
Oct 13, 2025 1 year earlier	127K	1	$2.1M
Oct 13, 2024 2 years earlier	1.09M	3	$15.6M
Oct 14, 2023 3 years earlier	0	0	$0
Oct 14, 2022 4 years earlier	0	0	$0
Oct 14, 2021 5 years earlier · filings don't cover the whole year	926K	3	$24.1M

Open-market sales (Form 4 code S) by people who were officers or directors, in split-adjusted shares. Earlier years include people who have since left. A sale that an outside holder also reports (a family trust, a fund) is counted with outside holders in every year. Shares, not dollars, are compared, so a change in the stock price doesn't look like a change in selling. Years the filings don't fully cover are shown but left out of the average.

Known gaps and uncertainty18 officers and directors not confirmed

Holdings and share of stake are being verified. Balances, unit counts and every share-of-stake figure for Sotera Health Co are held back until that check is finished. Sales, proceeds, plan and tax status, titles and dates come straight from individual filings and are complete.

External context: we only cite outside events when a documented connection exists. None is shown for this period.

Sources and methodology171 filings on record, 37 filed in the 12-month period, and how we read them

All 171 Forms 3, 4 and 5 on record for Sotera Health Co (SEC CIK 1822479), filed from Nov 20, 2020 to Aug 19, 2026; 37 of them were filed in the 12 months this page covers, retrieved from SEC EDGAR on Oct 13, 2026. Prices are the ones reported in each filing, often weighted averages.

Holdings. Each holding line (a share class plus an owner, such as a trust or LLC) carries its last reported balance forward. Entities first reported during the period start at zero, so transfers between an insider's own trusts don't count as selling. Lines not reported for three years or more are listed separately and left out of totals.

Sales. A sale counts as under a 10b5-1 plan if its footnote cites one or the filing's Rule 10b5-1 box is checked, and as tax-related if its footnote cites tax obligations or sell-to-cover. Shares withheld by the company for taxes are listed separately. Sales with neither attribute are labeled "no plan disclosed".

Full methodology

Former or inactive filers (6)No filing in 18 months; last reported balances, not in any total

Name	Last filed	Last reported balance
David Donnini	May 29, 2024	61,649 shares, last reported balance as of May 24, 2024
Matthew Klaben	Oct 7, 2022	351,989 shares, last reported balance as of Oct 1, 2022
Stephanie Geveda	May 31, 2022	25,848 shares, last reported balance as of May 27, 2022
Scott Leffler	Mar 4, 2022	1,443,749 shares, last reported balance as of Mar 2, 2022
Terry Hammons	Mar 4, 2022	31,257 shares, last reported balance as of Mar 2, 2022
Michael Biehl		No balance on record

Spotted something wrong on this page? Report an error. We check every report against the SEC filing and list what we fix in the corrections log.

Sotera Health Co insiders sold $36.3M in the past 12 months. How much of their stake is that?

What stands out

Who sold, and how much of their stake

Selling by month

Recent activity

Outside holders, reported separately

Common questions

Is the Sotera Health Co CEO selling stock?

Why are Sotera Health Co insiders selling?

Are any Sotera Health Co insiders buying?

The evidence

No plan disclosed · $36.3M

Taxes

Sales by month