O'Sullivan Michael J.

Form 4 filings across 2 companies. Net figures count open-market buys and sales only. EDGAR profile ↗

Lifetime net: -$2.8M

Positions by company

Reported holding is the most recent post-transaction share count on a Table I row.

Every company this insider has reported trading in, with the value bought and sold at each and the date they last traded.
Ticker	Company	Bought	Sold	Net	Shares held	Last trade
BRK.A	Berkshire Hathaway INC	$500.6K	$0	+$500.6K	1,151	Aug 12
SNAP	Snap Inc	$0	$3.3M	-$3.3M	550,548	Nov 17, 2025

BRK.A

Berkshire Hathaway INC

+$500.6K

Bought

$500.6K

Sold

Held

1,151

SNAP

Snap Inc

-$3.3M

Bought

Sold

$3.3M

Held

550,548

Filing record

How quickly this filer reports. Section 16 allows two business days from the transaction.

All 12 filings we hold were filed within the two-business-day deadline.

Counted in business days from the transaction date, or the deemed execution date where the filing reports one, excluding weekends and federal holidays. How this is measured · All late filings

Trade history

The 27 most recent Form 4 transactions.

Insider transactions, newest first: date, security, transaction type, size and a link to the filing each row came from.
Date	Ticker	Company	Type	Shares	Price	Value	Δ Own	Filing
Aug 12	BRK.A	Berkshire Hathaway INC	PBUY	43	$513.61	$22.1K	+3.9%	Open the original filing on SEC.gov
Aug 12	BRK.A	Berkshire Hathaway INC	PBUY	400	$512.52	$205K	+56.5%	Open the original filing on SEC.gov
Aug 12