Who Was Buying the Week the Fed Hiked? Berkshire, a Homebuilder, and the CEOs Who Spent Their Own Money
When a company’s executives, directors or largest shareholders buy its stock with their own money, they have to tell the public within two business days on a form called a Form 4. Investor Sam ingests every one of those filings from the SEC — about 858,000 transactions so far — so we can answer a question no headline can: in the week the Federal Reserve raised rates for the first time since 2023, who was actually buying? The short answer is that most insiders did nothing, one very famous buyer did a lot, and a handful of chief executives put a million dollars or more of their own cash on the table. Here is the full picture, in plain language.
First, why insider buying is worth reading at all
Insiders sell for a hundred reasons — a house, taxes, diversification, a pre-scheduled plan. They buy for one: they think the shares are worth more than the price. That asymmetry is why open-market purchases (coded “P” on the form) get attention and sales mostly do not. Three things make a purchase more meaningful:
- It is open-market, not a stock award. Grants and option exercises are compensation. A purchase is a decision.
- It is large relative to the person. A director buying $50,000 of stock is a gesture; a chief executive buying $10 million is a position.
- Several insiders buy at once, or someone buys into a falling share price. A cluster of buys, or a buy after a 40% drop, says the people with the most information disagree with the market.
Insider buying is not a guarantee of anything. Insiders are early and wrong all the time. But it is one of the few signals in investing where the person sending it is risking their own money, and that makes it worth a look every time.
The week in numbers: a quiet one
We pulled every open-market purchase and sale by insiders dated September 14 through 22 — the seven trading days around the Fed’s decision on the 16th — and compared them with the four weeks before.
| Hike week (7 trading days) | Prior four weeks (20 trading days) | Per trading day, hike week vs before | |
|---|---|---|---|
| Open-market purchases | 309 transactions, $0.35bn, 121 companies | 1,676 transactions, $2.16bn, 473 companies | $50m a day vs $108m a day |
| Open-market sales | 1,367 transactions, $2.62bn, 358 companies | 8,512 transactions, $16.8bn, 1,297 companies | $374m a day vs $840m a day |
| Sales per dollar of purchases | $7.50 | $7.80 | Unchanged |
Two honest conclusions. First, there was no rush to buy the hike: purchases fell by more than half per day, and so did sales. Mid-September is when many companies close their trading windows ahead of quarter-end, so insiders at most large firms could not have traded even if they wanted to. Second, the ratio of selling to buying did not move. Insiders as a group were neither more nor less confident after the Fed than before. Anyone telling you “insiders are piling in” or “insiders are fleeing” this week is describing a few names, not the market.
Those few names are the interesting part.
The headline: Berkshire Hathaway bought a homebuilder the week mortgages hit 7%
The largest open-market purchase in our data for the week was not by an executive. It was by Berkshire Hathaway, which reported buying about 2.74 million shares of Lennar (LEN), one of the two biggest U.S. homebuilders, for roughly $212 million across September 17, 18 and 21 — the three trading days immediately after the Fed’s decision — at prices between $74.80 and $79.41. The purchases were disclosed in a Form 4 filed on September 21, and they lifted Berkshire’s stake to about 23.7 million Class A shares plus a smaller Class B holding.
Think about the timing. The Fed had just raised rates, the 10-year Treasury had crossed 5% the week before, and the average 30-year mortgage had climbed back above 7%. Homebuilders are the most rate-sensitive industry on the stock market, and Lennar’s shares were down about 34% over the past year when our data was computed, and further since. Berkshire bought into exactly that.
What the Lennar ratios page shows is why a value investor might. Lennar’s book value — what the company’s assets are worth on paper after debts — was about $68 a share at its last annual filing, so Berkshire paid roughly 1.1 times book. Debt-to-equity is a modest 0.56. Our verdict is HOLD, but look at the pillars: financial health scores 90, value scores 74 (one of the highest in our large-cap coverage), and the only weak pillar is momentum at 12, which is a measure of the share price, not the business. Profitability has fallen — net margin dropped from 11% to 6% as the company cut prices to keep selling homes into higher rates — and that is precisely the trough a long-term buyer looks for.
The chief executives who bought with their own money
Filtering to officers and directors — the people who run the companies — the notable open-market purchases in the week were:
| Company | Who | Date | Amount | Context from the filings |
|---|---|---|---|---|
| Fox Corp (FOX) | Lachlan Murdoch, Executive Chair and CEO | Sept 15 | $10.3m (149,934 shares at $68.53) | Rated BUY; financial health 100 (net cash), return on equity 14.5%, shares up 28% in three months. A large buy into strength, one day before the Fed. |
| Truist Financial (TFC) | Michael Lyons, President and CEO | Sept 17 | $1.0m (21,000 shares at $48.36) | A bank CEO buying the day after the hike. Our verdict shows STRONG SELL, but that is the bank-lens problem explained in our bank-stock guide; the usable figure is a 7.6% return on equity, low for a large bank. |
| Celsius Holdings (CELH) | Two directors, Damon DeSantis and Hal Kravitz | Sept 14–15 | $1.3m combined | A cluster buy into a stock down 43% over the year. Rated SELL on a growth score of zero — the directors are betting the growth comes back. |
| Cooper Companies (COO) | Two directors, Lawrence Kurzius and Walter Rosebrough | Sept 14–16 | $1.25m combined | Another cluster buy into weakness: shares down 17% over the year, 21% in three months. Value pillar 69. |
| Star Bulk Carriers (SBLK) | Eight officers and directors | Sept 15 | $6.9m combined | The widest cluster of the week: the co-CFO, COO, chief strategy officer and five directors buying on the same day. Shipping rates rise when Middle East routes are disrupted; the momentum pillar is 100. |
Two purchases that were not by executives but are large enough to note: an investment firm that already owns more than 10% of Group 1 Automotive (GPI) bought a further $16.9 million on September 17–18, into a stock down 45% over the year with a value pillar of 75; and five directors and a holding company bought $12 million of CPI Card Group on September 14. Separately, press reports say GameStop’s chief executive bought about $26 million of shares on September 21, continuing a run of purchases; that filing landed after our cut-off, so it is not in the table.
And the sellers
For balance: insiders at Nvidia (NVDA) sold about $308 million of stock in the week, split between two people, and a single Microsoft (MSFT) insider sold $21 million. Sales of that size at companies whose shares have risen enormously are almost always pre-scheduled selling plans, and they carry little information. The interesting fact is the one the numbers make obvious: the insiders with the most to sell are at the AI companies that just rallied, and the insiders buying are at the homebuilders, banks and consumer names that did not.
How to use this without fooling yourself
- Read the size, not the headline. Lachlan Murdoch’s $10 million and Berkshire’s $212 million are positions. A director’s $50,000 is a courtesy.
- Prefer clusters and buys into weakness. Star Bulk’s eight insiders on one day, and the Celsius and Cooper directors buying after 20–40% falls, are the pattern that historically means something.
- Then do the work. An insider buy is a reason to open the filings, not a reason to skip them. Every company above has a page with its balance sheet, income statement and verdict; the insider’s reasoning is usually visible in one of them.
- Ask. On any company page, Ask Sam will answer “have insiders bought or sold recently?” from the same Form 4 data used here, with dates and amounts. The superinvestor tracker covers what the big funds hold, and congressional trades cover the other group of people who file their trades in public.
Frequently asked questions
Why did Berkshire have to file a Form 4 at all?
Form 4 applies to officers, directors and anyone who owns more than 10% of a company’s stock. Berkshire’s Lennar stake is large enough to trigger that rule, which is why its purchases appear within two business days rather than in a quarterly 13F filing months later. It is one of the few ways to see Berkshire buy in near-real time.
Does insider buying predict returns?
Academic studies over several decades find that open-market purchases, especially clusters and purchases by top executives, are followed by modestly better-than-market returns on average over the next year. The effect is real but not large, and it works on average across many stocks, not reliably on any single one. Treat it as a reason to look, not a reason to buy.
Where do these figures come from?
From Form 4 filings on SEC EDGAR, ingested into Investor Sam’s insider-transactions database, covering transactions dated September 14–22, 2026 and filed by September 23. Filings can arrive up to two business days after a trade, so a few late purchases from September 21–22 may not be included. Verdict and ratio figures are from each company’s most recent annual filing.
Sources
- U.S. Securities and Exchange Commission — Forms 4 filed September 14–23, 2026, via EDGAR, including Berkshire Hathaway’s Form 4 for Lennar Corporation filed September 21, 2026 (accession 0001193125-26-397059).
- Company annual filings via SEC EDGAR for LEN, DHI, PHM, FOX, TFC, CELH, COO, SBLK, GPI, NVDA and MSFT; verdicts and ratios as computed on Investor Sam.
- Federal Reserve Board — FOMC statement, September 16, 2026; Freddie Mac and daily mortgage-rate surveys, September 2026.
- Press reports of the GameStop purchase: Yahoo Finance, September 22, 2026.