
Nippon Life bought Corebridge stock daily Sept. 9-30. The merger roughly halves its share.
Nippon Life spent $142.8 million on Corebridge stock from Sept. 9 to Sept. 30, by KeyVex's tally of its filings. Six months after the Equitable merger closes, its stake in the new company sets how many directors it may name.
KeyVex News··6 min readFact-checked against 26 public records
KeyVex News··6 min readFact-checked against 26 public records
CRBG$34.03▲ 1.1%Close, Oct. 2. Prices from Tiingo.The short versionTap to readTap to close
- In an all-stock merger, both sides' holders get new shares, so a big holder's percentage shrinks. The merger proxy puts Nippon Life, Corebridge's largest holder, at about 13.9% of the new Equitable.
- Nippon's directly held Corebridge shares didn't change for almost two years after its 2024 purchase. Then it bought on every trading day from Sept. 9 to Sept. 30, under a prearranged plan.
- Each Corebridge share becomes one share of the new company, so that buying raises Nippon's stake in it. Buybacks by either company raise it too.
- For six months after closing, Nippon may name two directors; then its seats equal its stake times the board's size, rounded down. Its filings don't connect its purchases to those board rights.
- The purchase plan can run no later than Dec. 8, by KeyVex's reading of Nippon's filing. The companies expect to close by year-end, subject to regulators.
The buying: Nippon Life Insurance, the Japanese insurer that is Corebridge Financial's largest shareholder, bought Corebridge stock on all 16 trading days from Sept. 9 to Sept. 30, its Form 4 filings show.Form 4Form 4All 16 A Form 4 is the report a company's officers, directors and holders of more than 10% file on their trades.Investor.gov It paid about $142.8 million for 4.2 million shares. That took it to about 28% of Corebridge as of Sept. 30, by KeyVex's math.Form 410-Q
The merger: In March, Corebridge agreed to combine with Equitable Holdings in an all-stock deal, and both companies' shareholders approved it on July 30.Release8-K The combined company keeps the Equitable name and will be based in Houston, where Corebridge is.Release The merger proxy puts Nippon at about 13.9% of it. That figure does not count Nippon's purchases or any buybacks.Proxy
Why it matters: The merger turns the owner of more than a quarter of Corebridge into the owner of about 14% of a bigger company. Nippon had three representatives on Corebridge's board in March.Release After closing, it may name two directors for six months. Then its seats equal its stake times the size of the board, rounded down. The board is set at 14.Proxy
Corebridge's stock and Nippon Life's filingsDaily close, March 2 to Oct. 2, 2026 ▲ 31.0%Show chartHide chart
How a fifth became more than a quarter
Nippon Life bought its Corebridge stake from AIG. On Dec. 9, 2024, it paid about $3.8 billion for 122 million shares, or $31.47 each. That was 21.6% of Corebridge at the time.8-K13D
Nippon's filing then was a Schedule 13D, the form for holders of more than 5% who may seek to influence a company. It said Nippon wanted to expand its global business and had sought to invest in growing U.S. life insurance and retirement companies. It also said Nippon "may acquire additional securities" of Corebridge, or sell some or all of its shares. Its agreement with Corebridge bars it from going above 30% of the stock without the board's approval.13D8-K
For almost two years, the shares Nippon held directly stayed at 121,956,256, its August filing shows. Its stake still grew, to 27.4%, as Corebridge bought back its own stock.13D/A In the first half of 2026 alone, Corebridge repurchased about 52 million shares.10-Q
View the data
| As of | Nippon Life's stake | Note |
|---|---|---|
| Dec. 9, 2024 | 21.6% | 121,956,256 shares bought from AIG; Corebridge 8-K |
| Aug. 7, 2026 | 27.4% | Same shares held of record, plus 33,271 at a subsidiary; 13D amendment |
| Sept. 30, 2026 | 28.3% | 126,144,687 shares over 445,772,522 outstanding on July 31; KeyVex's math |
| At the merger | 13.9% | Of the new Equitable, per the merger proxy, not counting buybacks or Nippon's purchases |
The first three columns are shares of Corebridge; the last is of the combined company, before Nippon's purchases or any buybacks. Sept. 30 is KeyVex's math. Sources: Corebridge 8-K, Dec. 10, 2024; Nippon Life 13D amendment, Aug. 7, 2026; Form 4, Oct. 2, 2026; Corebridge 10-Q; merger proxy, June 23, 2026.
What the merger does to the stake
The deal swaps each Corebridge share for one share of the combined company, and Equitable's holders get shares too. Corebridge's holders end up with about 51% of the new company and Equitable's with about 49%.Release So Nippon's percentage roughly halves.Proxy
Nippon backed the deal from the start. Its three representatives on Corebridge's board voted for it. "Nippon expects to continue as a long-term strategic investor," its president, Satoshi Asahi, said in the March 26 announcement.Release On April 8 it agreed to vote its shares for the merger.Proxy
At closing, Nippon and the new Equitable sign a stockholder's agreement, the contract that sets Nippon's rights as a shareholder. Once the first six months are over, the proxy says, Nippon may name a number of directors, rounded down to a whole number,Proxy
equal to the product of the total number of directors multiplied by the share ownership percentage of Nippon Life
That formula runs until Nippon's stake falls below 5%. Other rights end at other levels. It may inspect the company's books and records until it falls below 10%. Three Nippon employees may work at the new company for at least six months, and until its stake falls below 15%. The agreement also bars it from going above 30% without the board's approval.Proxy
On a 14-member board, the formula gives one seat for a stake from about 7.1% up to 14.29%, and two seats from 14.29%, which is 2 divided by 14.Proxy The board's size can change after closing. Nippon's filings don't connect its purchases to its board rights. In June, before any of this buying, the proxy's 13.9% figure already set aside "potential" share purchases by Nippon.Proxy
The plan behind the buying
On Aug. 7, Nippon told the SEC it had set up a trading plan with Goldman Sachs International to buy up to 10,900,682 more Corebridge shares. The SEC's Rule 10b5-1 gives a defense against insider-trading claims for trades made under a contract, instruction or written plan adopted when the trader had no material nonpublic information.SEC Purchases under this one could begin only after a cooling-off period and any needed regulatory approvals, the amendment says.13D/A The amendment adds no reason for the new buying; the 2024 statement of purpose still stands.13D/A Every one of the 16 Form 4s says its purchases were made under that plan.Form 4Form 4
The biggest day was Sept. 28, at 805,782 shares. Nippon paid an average of about $34.37 a share, compared with $31.47 in 2024.Form 4All 1613D Through Sept. 30 the plan had used 38% of its cap, leaving room for about 6.7 million more shares, by KeyVex's math.13D/A
Shares Nippon Life bought each trading day, Sept. 9 to Sept. 30Show chartHide chart
View the data
| Trade date | Shares bought | Note |
|---|---|---|
| Sept. 9 | 136,466 shares | |
| Sept. 10 | 176,300 shares | |
| Sept. 11 | 171,144 shares | |
| Sept. 14 | 295,967 shares | |
| Sept. 15 | 210,903 shares | |
| Sept. 16 | 320,785 shares | |
| Sept. 17 | 174,760 shares | |
| Sept. 18 | 131,333 shares | |
| Sept. 21 | 212,828 shares | |
| Sept. 22 | 296,868 shares | |
| Sept. 23 | 219,273 shares | |
| Sept. 24 | 258,878 shares | |
| Sept. 25 | 178,840 shares | |
| Sept. 28 | 805,782 shares | |
| Sept. 29 | 216,818 shares | |
| Sept. 30 | 348,215 shares |
4,155,160 shares in all, for about $142.8 million at the weighted-average prices reported. Source: 16 Nippon Life Form 4 filings, Sept. 11 to Oct. 2, 2026.
What else moves the number
Buybacks raise Nippon's percentage too. On the March 26 call, Equitable finance chief Robin Raju said both companies would stay out of the market until the shareholder vote, and would look to buy back stock between the vote and the closing, according to a transcript filed with the SEC. Any planned buybacks not done by then would be done in one large repurchase at or shortly after closing, he said.Transcript
The merger still needs regulators. Corebridge chief executive Marc Costantini said on Sept. 9 that the companies were working through "four or five key states." Speaking at an investor conference held by the bank KBW, he spoke of Jan. 1 "when we hope to close," according to a transcript Corebridge filed.Transcript
Nippon's plan ends once it has bought 10,900,682 shares, 90 days after it took effect, or on other conditions, the 13D amendment says. By KeyVex's reading, those 90 days run out no later than Dec. 8.13D/A
The paper trail
Nippon Life's Corebridge filings and the merger filings this story cites, Dec. 10, 2024 through Oct. 2, 2026, with the time EDGAR accepted each one where it matters.
| Filed (ET) | Form | Filer | What it shows |
|---|---|---|---|
| Dec. 10, 2024 | 8-K | Corebridge | Nippon Life completes its purchase of 121,956,256 shares from AIG, 21.6%. |
| Dec. 13, 2024 | 13D | Nippon Life | Price of $31.4704 a share; 30% ceiling; it "may acquire additional securities." |
| March 26, 2026 | 8-K, Ex. 99.1 | Equitable | Joint release: all-stock merger with Corebridge; 14-member board. |
| June 23, 4:45 p.m. | DEFM14A | Corebridge | Joint proxy: Nippon about 13.9% of the new company; its new stockholder's agreement. |
| July 30, 4:35 p.m. | 8-K | Corebridge | Shareholders of both companies approve the merger. |
| Aug. 7, 4:05 p.m. | 13D/A | Nippon Life | 27.4%; trading plan to buy up to 10,900,682 shares. |
| Sept. 9, 9:36 p.m. | 425 | Corebridge | KBW conference transcript; the CEO on regulators and a hoped-for Jan. 1 close. |
| Sept. 11, 4:15 p.m. | 4 | Nippon Life | First purchase under the plan: 136,466 shares on Sept. 9. |
| Sept. 30 | 4 | Nippon Life | The largest day: 805,782 shares on Sept. 28. |
| Oct. 2, 4:30 p.m. | 4 | Nippon Life | 348,215 shares on Sept. 30; 126,144,687 owned after. |
What to watch
The latest the plan can run: 90 days after it took effect, which was no later than Sept. 9, the first purchase (KeyVex's reading of the 13D).
The companies' target to close the merger, subject to regulators.
Nippon's two board seats for the first six months give way to the stake-based formula.
Sources
30 sources, 26 of them public records
Public records
- Nippon Life Insurance Co., Schedule 13D Amendment No. 4 for Corebridge FinancialSEC EDGAR · Aug. 7, 2026
- Nippon Life Insurance Co., Schedule 13D for Corebridge FinancialSEC EDGAR · Dec. 13, 2024
- Form 4, Nippon Life Insurance Co. (Sept. 9 purchase)SEC EDGAR · Sept. 11, 2026
- Form 4, Nippon Life Insurance Co. (Sept. 10 purchase)SEC EDGAR · Sept. 14, 2026
- Form 4, Nippon Life Insurance Co. (Sept. 11 purchase)SEC EDGAR · Sept. 15, 2026
- Form 4, Nippon Life Insurance Co. (Sept. 14 purchase)SEC EDGAR · Sept. 16, 2026
- Form 4, Nippon Life Insurance Co. (Sept. 15 purchase)SEC EDGAR · Sept. 17, 2026
- Form 4, Nippon Life Insurance Co. (Sept. 16 purchase)SEC EDGAR · Sept. 18, 2026
- Form 4, Nippon Life Insurance Co. (Sept. 17 purchase)SEC EDGAR · Sept. 21, 2026
- Form 4, Nippon Life Insurance Co. (Sept. 18 purchase)SEC EDGAR · Sept. 22, 2026
- Form 4, Nippon Life Insurance Co. (Sept. 21 purchase)SEC EDGAR · Sept. 23, 2026
- Form 4, Nippon Life Insurance Co. (Sept. 22 purchase)SEC EDGAR · Sept. 24, 2026
- Form 4, Nippon Life Insurance Co. (Sept. 23 purchase)SEC EDGAR · Sept. 25, 2026
- Form 4, Nippon Life Insurance Co. (Sept. 24 purchase)SEC EDGAR · Sept. 28, 2026
- Form 4, Nippon Life Insurance Co. (Sept. 25 purchase)SEC EDGAR · Sept. 29, 2026
- Form 4, Nippon Life Insurance Co. (Sept. 28 purchase)SEC EDGAR · Sept. 30, 2026
- Form 4, Nippon Life Insurance Co. (Sept. 29 purchase)SEC EDGAR · Oct. 1, 2026
- Form 4, Nippon Life Insurance Co. (Sept. 30 purchase)SEC EDGAR · Oct. 2, 2026
- Corebridge Financial and Equitable Holdings, joint proxy statement/prospectus (DEFM14A)SEC EDGAR · June 23, 2026
- "Corebridge Financial and Equitable Holdings Announce Transformational Merger" (Exhibit 99.1)SEC EDGAR · March 26, 2026
- Corebridge Financial, Form 8-K: results of the special meetingSEC EDGAR · July 30, 2026
- Corebridge Financial, Form 8-K: AIG's agreement to sell shares to Nippon LifeSEC EDGAR · May 16, 2024
- Corebridge Financial, Form 8-K: Nippon Life completes its purchaseSEC EDGAR · Dec. 10, 2024
- Corebridge Financial, Form 10-Q for the quarter ended June 30, 2026SEC EDGAR · Aug. 5, 2026
- Transcript of the March 26, 2026 Corebridge and Equitable merger call (Form 425)SEC EDGAR · March 26, 2026
- KBW Insurance Conference transcript, Corebridge Financial, Sept. 9, 2026 (Form 425)SEC EDGAR · Sept. 10, 2026
Rules and references
- Rule 10b5-1: Insider Trading Arrangements and Related Disclosure (fact sheet)U.S. Securities and Exchange Commission · Dec. 2022
- Forms 3, 4 and 5 (glossary)Investor.gov, U.S. Securities and Exchange Commission · accessed Oct. 5, 2026
Data
- End-of-day prices for CRBG, and for SPY and QQQ on the chart (Tiingo)KeyVex · through Oct. 2, 2026
- The chart's Filings layer: KeyVex's Congress trade, insider trade, Form 144, 8-K and lobbying records for CRBGKeyVex · through Oct. 2, 2026
How we got these numbers
- Prices are end-of-day closes as traded, not adjusted for dividends. The S&P 500 and Nasdaq 100 lines follow SPY and QQQ, rebased to Corebridge's close at the start of the range shown. The Filings switch shows the filing markers from KeyVex's Corebridge page, a selection of filings: not every filing, and not only those tied to this story.
- Purchases: 18 lines on 16 Form 4s, 4,155,160 shares. Dollar totals are shares times the weighted-average price on each line: $142,809,046, an average of $34.37 a share. Nippon's holding after Sept. 30, 126,144,687 shares, includes 33,271 held by its subsidiary Nissay Asset Management.
- Share of Corebridge: 126,144,687 shares over the 445,772,522 Corebridge reported outstanding on July 31, 2026 (28.3%). The full plan, 132,890,209 shares, would be 29.8% on that count. The 13D amendment's 27.4% uses 445,768,608 shares as of June 22.
- Share of the new Equitable: the proxy's figure is about 13.9%, not counting buybacks or Nippon's purchases. KeyVex does not estimate the stake after the September purchases: the share counts of both companies have changed since the proxy's June 1 counts by more than the margin such an estimate would need, and buybacks at either company raise it.
- Board seats: on 14 directors, two seats require 2/14, or 14.29%, under the formula, which applies only after the first six months. The board's size after closing may change. The filings do not say how the purchase plan's size was set.
- The latest end date for the plan is KeyVex's reading: the 13D amendment says purchases begin on the plan's Effective Date and the plan ends no later than 90 days after it; the first purchase was Sept. 9, so the Effective Date was no later than that.





