Transactions
5
Insider / BERKSHIRE HATHAWAY INC
O'Sullivan Michael J.
See Remarks at BERKSHIRE HATHAWAY INC
- Company
- BERKSHIRE HATHAWAY INC
- First filing on record
- May 6, 2026
- Latest trade on record
- August 12, 2026
- SEC filings
- EDGAR ↗
O'Sullivan Michael J., See Remarks at BERKSHIRE HATHAWAY INC, has disclosed 5 transactions in BRK.B, BRK-B since May 6, 2026: 5 purchases (5 open-market buys) and 0 sales, worth about $501K at the reported prices. The latest was filed August 13, 2026, 1 day after the trade.
Open-market buys
5
Sales
0
Avg. disclosure lag
0.6d
Trading in charts
Trade timeline
When does this person trade, how big, and in which direction? Every trade in the last 12 months.
Bought (above the line)Sold (below the line)
In the last 12 months O'Sullivan Michael J. made 5 purchases worth $501K and no sales. Dot size is the dollar amount.
Portfolio mix
Which stocks does this person trade most? Tile size is dollars traded, all time on record.
O'Sullivan Michael J. has traded 2 stocks on record; the largest by dollars is BRK-B.
Reporting lag
Does this person report on time? One bar per filing against the Form 4 deadline.
On timeLate
0 of 2 filings on record were reported after the Form 4 deadline (two business days, counted here as 4 calendar days).
What kind of transactions
Most Form 4 rows are pay arriving or tax being withheld, not a decision to buy or sell. Only code P is an open-market purchase and code S an open-market sale. What each code means: Form 4 transaction codes.
| Code | Meaning | Rows | Shares | Value |
|---|---|---|---|---|
| P | Open-market purchase | 5 | 1,024 | $501K |
| Year | Rows | Bought | Sold |
|---|---|---|---|
| 2026 | 5 | 5 · $501K | 0 |
Transactions
| Security | Side | Trade date | Disclosed | Lag | Shares | Price | Value | Flags | Source | Share |
|---|---|---|---|---|---|---|---|---|---|---|
| BRK.B | Buy P | August 12, 2026 | August 13, 2026 | 1d | 43 | $514 | $22K | indirect | Form 4 ↗ | |
| BRK.B | Buy P | August 12, 2026 | August 13, 2026 | 1d | 400 | $513 | $205K | indirect | Form 4 ↗ | |
| BRK.B | Buy P | August 12, 2026 | August 13, 2026 | 1d | 45 | $511 | $23K | indirect | Form 4 ↗ | |
| BRK-B | Buy P | May 6, 2026 | May 6, 2026 | 0d | 53 | $470 | $25K | indirect | Form 4 ↗ | |
| BRK-B | Buy P | May 6, 2026 | May 6, 2026 | 0d | 483 | $467 | $226K | indirect | Form 4 ↗ |
Filings
| Filed | Form | Accession | Rows | Status | Source |
|---|---|---|---|---|---|
| August 13, 2026 | Form 4 | 0001193125-26-349574 | 3 | published | EDGAR ↗ |
| May 6, 2026 | Form 4 | 0001193125-26-209661 | 2 | published | EDGAR ↗ |
Other insiders at BERKSHIRE HATHAWAY INC
- Abel Gregory E. See Remarks 18 rows
- BUFFETT WARREN E Director 18 rows
- Jain Ajit Vice Chairman 6 rows
- GUYMAN CHARLOTTE Director 4 rows
- Chang Charles C See Remarks 2 rows
Everyone on file, with contracts and lobbying under the company's name: BERKSHIRE HATHAWAY INC.
Guides for this page
- What is SEC Form 4? Who files: officers, directors and owners of more than 10% of a class of the company's shares.
- Form 4 transaction codes P = purchase. S = sale. These are the two market trades.
- Insider buying vs insider selling Selling outweighs buying by a wide margin in normal times.
- What disclosure data cannot tell you Filings are late by design: up to 45 days for Congress, two business days for insiders.
Sources and method
| Source | Filings | Rows | First filed | Newest filed | Read the originals |
|---|---|---|---|---|---|
| SEC EDGAR, Form 4 | 2 | 5 | May 6, 2026 | August 13, 2026 | Form 4 list on EDGAR |
Site built October 27, 2026. Every row in the tables above links to its own filing. To quote a figure, use the Cite button at the top of the page; see how to cite and reuse.
Every row comes from the reporting owner's Form 4 as filed with the SEC (EDGAR ownership XML), read daily. "Value" is shares × the reported price; code P is an open-market purchase, S a sale, M an option exercise, A a grant. The lag is the filing date minus the trade date; Form 4 is due within two business days. Amendments (4/A) are not merged. Details on the methodology page; report an error on corrections.
Not investment advice. Figures are public disclosures shown as filed; they may lag the trade and may be amended later. No recommendation is made or implied.