What happened
Japan Post Holdings Co., Ltd., a 10% owner of Aflac Inc. (NYSE: AFL), sold 12,100 shares on 2026-09-29, according to the Form 4.
The filing shows two sale lots, 6,378 shares at $113.10 and 5,722 shares at $113.64, for about $1.37 million.
After the first sale, Japan Post held 50,451,012 shares. After the second, it held 50,445,290 shares.
The form was signed on 10/01/2026. It says the trades were made under a Rule 10b5-1 trading plan.
Key numbers
| Metric | Latest | Change | Source |
|---|---|---|---|
| Shares sold | 12,100 shares | SEC Form 4 | |
| Price per share | $113.10 to $113.64 | SEC Form 4 | |
| Sale value | about $1.37 million | SEC Form 4 | |
| Shares held after sale | 50,445,290 shares | SEC Form 4 | |
| Sale as share of pre-sale holding | about 0.0% | Calculated from SEC Form 4 |
Read more: Aflac (AFL) stock analysis and investment case
Why it matters
OptimistFi's case is that Aflac creates durable value through sticky supplemental insurance premiums and a strong capital base.
This filing does not change that view. It shows a small, planned sale by a large holder, not a shift in Aflac's business.
OptimistFi's calculation puts the 12,100 shares at about 0.0% of the pre-sale holding.
That makes the trade look like a modest trim of a very large position. Japan Post still held 50,445,290 shares after the sale.
The main caution is that the seller remains a 10% owner, so later Form 4s could still show more sales under the same plan.
For Aflac, the filing reads more like an ownership update than a business update.
The sale is tiny beside the remaining stake, so the read-through is limited.
It does not by itself change the case built on premium flows and capital returns.
Browse: stock research on every company OptimistFi covers
What's next
The next check is any later Form 4 from Japan Post Holdings Co., Ltd.
If later filings show more sales under the same Rule 10b5-1 plan, the read-through should stay muted.
If the stake stops changing, this filing remains a one-off reduction and the case stays unchanged.
Either way, the form sets the ownership mark at 50,445,290 shares after the 2026-09-29 trades.
Those numbers now serve as the baseline for any later report.
More from OptimistFi
- AFL stock: the Aflac thesis, its status and the next test to watch
- Broadcom Inc. (NASDAQ: AVGO) Adds AI Substrate Capacity
- Does CoreWeave, Inc. (NASDAQ: CRWV) Forge Diversify Revenue?
- Micron Technology, Inc. (NASDAQ: MU) Guides to $61.5 Billion
- Stock research on every company OptimistFi covers
- Latest stock research and investment-case updates
- OptimistFi: evidence-first equity research
Sources
- SEC Form 4 — Form 4 reporting Japan Post Holdings Co., Ltd.'s sales of Aflac common stock on 2026-09-29 and the post-sale holding.
Read the full OptimistFi thesis on Aflac Inc: https://optimistfi.com/stocks/AFL
See what would break the Aflac Inc thesis and track it live on the OptimistFi Thesis-Break Engine.
Browse every company OptimistFi covers at optimistfi.com/stocks, or read the latest evidence-first research.
The full Aflac Inc investment case, its status and the next test to watch live on the Aflac Inc thesis page.
Originally published on OptimistFi, evidence-first equity research. More at optimistfi.com.
