Person · CIK 1769845

Mark J. Day

No filings in the last two years

Earlier: iRhythm Technologies

Source: Forms 3, 4, 5 and 144 on SEC EDGAR

Sold on Form 4$6.8M

Noticed on Form 144$300K

Bought on Form 4$0

Companies1

Holdings now

As reported after the latest Form 3, 4 or 5 at each company.

How these figures work

Options and RSUs are from the latest filing that lists them; earlier grants may also be held. Holdings can be out of date when a person stops filing.

Company	Security	Held	Shares or units	As of
iRhythm Technologies	Common Stock	Directly	61,164	Mar 4, 2024 · Filing · EDGAR
iRhythm Technologies	Employee Stock Option (right to buy) exercise $36.22, expires Feb 8, 2027, into Common Stock	Directly	13,591	Aug 3, 2023 · Filing · EDGAR

Sold and noticed by quarter

Sold (Form 4) Noticed (Form 144) Bought (Form 4)

Quarterly totals as a table

Quarter	Sold (Form 4)	Noticed (Form 144)
Q2 2024	—	$300K
Q1 2024	$541K	—
Q1 2023	$473K	Not machine-readable
Q1 2022	$826K	Not machine-readable
Q4 2020	$4M	Not machine-readable
Q3 2020	$918K	Not machine-readable

Form 144 notices went onto EDGAR as structured data on April 13, 2023. Earlier notices were filed on paper and cannot be read here, so those quarters show no noticed amount.

Planned sales (Form 144) and the sales that followed

Each Form 144 notice of a planned sale, grouped by broker and 10b5-1 plan, with the Form 4 sales we matched to it.

How we match

A Form 144 is a notice of a planned sale by an affiliate. SEC Tracker matches each notice to Form 4 sales by the same person at the same company within 90 days of the notice, up to the shares noticed. The match is our inference, not something either filing states.

Notice date	Noticed	Planned sale	Outcome	Links
iRhythm Technologies · Morgan Stanley Smith Barney · 10b5-1 plan adopted Mar 13, 2024 · 1 notice
Jun 18, 2024	3,000 · ~$300K	Jun 18, 2024	Not sold within 90 days	Filing · EDGAR
Sales without a matching Form 144 · 23 sales No matching Form 144 found. Not every sale needs one: small sales and sales by people who are not affiliates are exempt.
—	—	—	Sold without notice iRhythm Technologies: Sold 3,248 at $111.14 on Mar 4, 2024 · $361K	Filing · EDGAR
—	—	—	Sold without notice iRhythm Technologies: Sold 1,475 at $121.96 on Feb 29, 2024 · $180K	Filing · EDGAR
—	—	—	Notice not machine-readable iRhythm Technologies: Sold 2,116 at $117.23 on Mar 3, 2023 · $248K	Filing · EDGAR
—	—	—	Notice not machine-readable iRhythm Technologies: Sold 15 at $119.28 on Feb 28, 2023 · $2K	Filing · EDGAR
—	—	—	Notice not machine-readable iRhythm Technologies: Sold 1,898 at $117.83 on Feb 28, 2023 · $224K	Filing · EDGAR
—	—	—	Notice not machine-readable iRhythm Technologies: Sold 2,518 at $132.67 on Mar 4, 2022 · $334K	Filing · EDGAR
—	—	—	Notice not machine-readable iRhythm Technologies: Sold 3,975 at $121.04 on Feb 17, 2022 · $481K	Filing · EDGAR
—	—	—	Notice not machine-readable iRhythm Technologies: Sold 87 at $118.93 on Feb 17, 2022 · $10K	Filing · EDGAR
—	—	—	Notice not machine-readable iRhythm Technologies: Sold 657 at $238.48 on Oct 1, 2020 · $157K (10b5-1 plan)	Filing · EDGAR
—	—	—	Notice not machine-readable iRhythm Technologies: Sold 1,146 at $236.88 on Oct 1, 2020 · $271K (10b5-1 plan)	Filing · EDGAR
—	—	—	Notice not machine-readable iRhythm Technologies: Sold 556 at $235.11 on Oct 1, 2020 · $131K (10b5-1 plan)	Filing · EDGAR
—	—	—	Notice not machine-readable iRhythm Technologies: Sold 8 at $231.20 on Oct 1, 2020 · $2K (10b5-1 plan)	Filing · EDGAR
—	—	—	Notice not machine-readable iRhythm Technologies: Sold 4,280 at $230.36 on Oct 1, 2020 · $986K (10b5-1 plan)	Filing · EDGAR
—	—	—	Notice not machine-readable iRhythm Technologies: Sold 4,406 at $229.45 on Oct 1, 2020 · $1M (10b5-1 plan)	Filing · EDGAR
—	—	—	Notice not machine-readable iRhythm Technologies: Sold 3,557 at $228.68 on Oct 1, 2020 · $813K (10b5-1 plan)	Filing · EDGAR
—	—	—	Notice not machine-readable iRhythm Technologies: Sold 2,280 at $227.52 on Oct 1, 2020 · $519K (10b5-1 plan)	Filing · EDGAR
—	—	—	Notice not machine-readable iRhythm Technologies: Sold 610 at $226.59 on Oct 1, 2020 · $138K (10b5-1 plan)	Filing · EDGAR
—	—	—	Notice not machine-readable iRhythm Technologies: Sold 243 at $187.70 on Aug 11, 2020 · $46K (10b5-1 plan)	Filing · EDGAR
—	—	—	Notice not machine-readable iRhythm Technologies: Sold 40 at $185.62 on Aug 11, 2020 · $7K (10b5-1 plan)	Filing · EDGAR
—	—	—	Notice not machine-readable iRhythm Technologies: Sold 360 at $184.96 on Aug 11, 2020 · $67K (10b5-1 plan)	Filing · EDGAR
—	—	—	Notice not machine-readable iRhythm Technologies: Sold 2,335 at $183.87 on Aug 11, 2020 · $429K (10b5-1 plan)	Filing · EDGAR
—	—	—	Notice not machine-readable iRhythm Technologies: Sold 1,586 at $182.96 on Aug 11, 2020 · $290K (10b5-1 plan)	Filing · EDGAR
—	—	—	Notice not machine-readable iRhythm Technologies: Sold 436 at $181.63 on Aug 11, 2020 · $79K (10b5-1 plan)	Filing · EDGAR

Every transaction, by company

Each Form 3, 4 and 5 transaction in plain words, newest first.

How these figures work

Values are shares times the price each filing states; grants, exercises and gifts usually state no price. Held after is what the filing reports was held once the transaction was done, directly or through the named holder.

iRhythm Technologies Chief Technology Officer · filings 2019 to 2024 · sold $6.8M · $300K noticed on Form 144

Date	Transaction	Shares	Price	Value	Held after	Source
Mar 4, 2024	Open-market or private sale	−3,248	$111.14	$361K	61,164 direct	Filing · EDGAR
Feb 29, 2024	Open-market or private sale	−1,475	$121.96	$180K	64,412 direct	Filing · EDGAR
Feb 28, 2024	Grant or award from the company	+7,734			65,887 direct	Filing · EDGAR
Feb 27, 2024	Grant or award from the company	+2,621			58,153 direct	Filing · EDGAR
Aug 3, 2023	Option or RSU exercised or converted	+486	$36.22	$18K	55,522 direct	Filing · EDGAR
Aug 3, 2023	Option or RSU exercised or converted Employee Stock Option (right to buy)	−486			13,591 direct	Filing · EDGAR
Mar 3, 2023	Open-market or private sale	−2,116	$117.23	$248K	54,815 direct	Filing · EDGAR
Feb 28, 2023	Open-market or private sale	−1,898	$117.83	$224K	56,946 direct	Filing · EDGAR
Feb 28, 2023	Open-market or private sale	−15	$119.28	$2K	56,931 direct	Filing · EDGAR
Feb 27, 2023	Grant or award from the company	+8,354			55,376 direct	Filing · EDGAR
Feb 27, 2023	Grant or award from the company	+3,468			58,844 direct	Filing · EDGAR
Mar 4, 2022	Open-market or private sale	−2,518	$132.67	$334K	46,705 direct	Filing · EDGAR
Feb 17, 2022	Open-market or private sale	−87	$118.93	$10K	53,198 direct	Filing · EDGAR
Feb 17, 2022	Open-market or private sale	−3,975	$121.04	$481K	49,223 direct	Filing · EDGAR
Feb 15, 2022	Grant or award from the company	+6,018			46,133 direct	Filing · EDGAR
Feb 15, 2022	Grant or award from the company	+7,152			53,285 direct	Filing · EDGAR
Mar 1, 2021	Grant or award from the company	+2,953			39,915 direct	Filing · EDGAR
Mar 1, 2021	Shares withheld for tax or exercise price	−2,518	$152.92	$385K	36,962 direct	Filing · EDGAR
Feb 23, 2021	Option or RSU exercised or converted	+8,300	$17.00	$141K	38,386 direct	Filing · EDGAR
Feb 23, 2021	Option or RSU exercised or converted	+971	$36.22	$35K	39,357 direct	Filing · EDGAR
Feb 23, 2021	Option or RSU exercised or converted	+123	$63.95	$8K	39,480 direct	Filing · EDGAR
Feb 23, 2021	Option or RSU exercised or converted Employee Stock Option (right to buy)	+8,300	$17.00	$141K	7,485 direct	Filing · EDGAR
Feb 23, 2021	Option or RSU exercised or converted Employee Stock Option (right to buy)	+971	$36.22	$35K	14,077 direct	Filing · EDGAR
Feb 23, 2021	Option or RSU exercised or converted Employee Stock Option (right to buy)	+123	$63.95	$8K	10,577 direct	Filing · EDGAR
Jan 17, 2021	Grant or award from the company	+10,353			34,664 direct	Filing · EDGAR
Jan 17, 2021	Shares withheld for tax or exercise price	−4,578	$250.57	$1.1M	30,086 direct	Filing · EDGAR
Dec 31, 2020	Option or RSU exercised or converted	+2,298	$8.18	$19K	22,811 direct	Filing · EDGAR
Dec 31, 2020	Option or RSU exercised or converted	+1,500	$17.00	$26K	24,311 direct	Filing · EDGAR
Dec 31, 2020	Option or RSU exercised or converted Employee Stock Option (right to buy)	−2,298			0 direct	Filing · EDGAR
Dec 31, 2020	Option or RSU exercised or converted Employee Stock Option (right to buy)	−1,500			15,785 direct	Filing · EDGAR
Oct 1, 2020	Sale under a 10b5-1 plan	−610	$226.59	$138K	37,369 direct	Filing · EDGAR
Oct 1, 2020	Sale under a 10b5-1 plan	−2,280	$227.52	$519K	35,089 direct	Filing · EDGAR
Oct 1, 2020	Sale under a 10b5-1 plan	−3,557	$228.68	$813K	31,532 direct	Filing · EDGAR
Oct 1, 2020	Sale under a 10b5-1 plan	−4,406	$229.45	$1M	27,126 direct	Filing · EDGAR
Oct 1, 2020	Sale under a 10b5-1 plan	−4,280	$230.36	$986K	22,846 direct	Filing · EDGAR
Oct 1, 2020	Sale under a 10b5-1 plan	−8	$231.20	$2K	22,838 direct	Filing · EDGAR
Oct 1, 2020	Sale under a 10b5-1 plan	−556	$235.11	$131K	22,282 direct	Filing · EDGAR
Oct 1, 2020	Sale under a 10b5-1 plan	−1,146	$236.88	$271K	21,136 direct	Filing · EDGAR
Oct 1, 2020	Sale under a 10b5-1 plan	−657	$238.48	$157K	20,479 direct	Filing · EDGAR
Aug 11, 2020	Sale under a 10b5-1 plan	−436	$181.63	$79K	42,543 direct	Filing · EDGAR
Aug 11, 2020	Sale under a 10b5-1 plan	−1,586	$182.96	$290K	40,957 direct	Filing · EDGAR
Aug 11, 2020	Sale under a 10b5-1 plan	−2,335	$183.87	$429K	38,622 direct	Filing · EDGAR
Aug 11, 2020	Sale under a 10b5-1 plan	−360	$184.96	$67K	38,262 direct	Filing · EDGAR
Aug 11, 2020	Sale under a 10b5-1 plan	−40	$185.62	$7K	38,222 direct	Filing · EDGAR
Aug 11, 2020	Sale under a 10b5-1 plan	−243	$187.70	$46K	37,979 direct	Filing · EDGAR
Mar 1, 2020	Shares withheld for tax or exercise price	−1,800	$86.97	$157K	42,677 direct	Filing · EDGAR
Feb 25, 2020	Grant or award from the company	+4,616			44,477 direct	Filing · EDGAR
Dec 31, 2019	Option or RSU exercised or converted	+638	$5.82	$4K	37,200 direct	Filing · EDGAR
Dec 31, 2019	Option or RSU exercised or converted	+2,661	$8.18	$22K	39,861 direct	Filing · EDGAR
Dec 31, 2019	Option or RSU exercised or converted Employee Stock Option (right to buy)	−638			0 direct	Filing · EDGAR
Dec 31, 2019	Option or RSU exercised or converted Employee Stock Option (right to buy)	−2,661			2,298 direct	Filing · EDGAR

All 20 Forms 3, 4, 5 and 144

Filed	Form	Company	Links
Jun 18, 2024	Form 144	iRhythm Technologies	Filing · EDGAR
Mar 5, 2024	Form 4	iRhythm Technologies	Filing · EDGAR
Mar 1, 2024	Form 4	iRhythm Technologies	Filing · EDGAR
Feb 29, 2024	Form 4	iRhythm Technologies	Filing · EDGAR
Aug 4, 2023	Form 4	iRhythm Technologies	Filing · EDGAR
Mar 7, 2023	Form 4	iRhythm Technologies	Filing · EDGAR
Mar 1, 2023	Form 4	iRhythm Technologies	Filing · EDGAR
Mar 8, 2022	Form 4	iRhythm Technologies	Filing · EDGAR
Feb 17, 2022	Form 4	iRhythm Technologies	Filing · EDGAR
Mar 22, 2021	Form 4/A	iRhythm Technologies	Filing · EDGAR
Mar 3, 2021	Form 4	iRhythm Technologies	Filing · EDGAR
Feb 25, 2021	Form 4	iRhythm Technologies	Filing · EDGAR
Jan 20, 2021	Form 4	iRhythm Technologies	Filing · EDGAR
Jan 5, 2021	Form 4	iRhythm Technologies	Filing · EDGAR
Oct 5, 2020	Form 4	iRhythm Technologies	Filing · EDGAR
Aug 13, 2020	Form 4	iRhythm Technologies	Filing · EDGAR
Mar 3, 2020	Form 4	iRhythm Technologies	Filing · EDGAR
Feb 27, 2020	Form 4	iRhythm Technologies	Filing · EDGAR
Jan 3, 2020	Form 4	iRhythm Technologies	Filing · EDGAR
Mar 27, 2019	Form 3	iRhythm Technologies	Filing · EDGAR

Every figure is as filed with the SEC on Forms 3, 4, 5 and 144. Holdings are the amounts reported after each person's latest filing at each company and can be out of date. Matching a Form 144 notice to Form 4 sales is SEC Tracker's inference from owner, company, dates and share counts, not something the filings state. Not investment advice. Not affiliated with the U.S. SEC.

Data on this page was fetched Nov 7, 2026, 1:38 AM ET. The filing on SEC.gov is the record.