Published July 11, 2026 · Finance-Solutes.com Research Desk

Vietnam’s largest listed jeweler just lived through one of its roughest stretches in years, and a well-known name in Vietnamese asset management made its move at a strikingly specific moment. On July 8, funds linked to VinaCapital sold roughly 3.1 million shares of Phu Nhuan Jewelry Joint Stock Company (HOSE: PNJ), trimming their combined related-party stake from 5.6% to essentially 4.9999% — just enough to drop out of “major shareholder” status under Vietnamese securities law. The timing stands out: July 8 was the only trading session in which PNJ shares actually rose since a criminal investigation into the company’s diamond-certification subsidiary, P-Lab, first made headlines.

In this piece, Finance-Solutes.com walks through what VinaCapital’s filing actually shows, the regulatory mechanics behind Vietnam’s 5% “major shareholder” threshold, what’s known so far about the P-Lab case, and what the sell-down alongside PNJ’s own response could mean for shareholders going forward.

Table of Contents

What Happened: VinaCapital’s Stake Sale, in Plain Terms

According to a filing sent to the State Securities Commission and the Ho Chi Minh Stock Exchange, five funds managed by VinaCapital Fund Management sold a combined 3.09 million PNJ shares in the July 8 session. Before the sale, this group of funds held about 6.35 million shares, equal to 1.241% of PNJ’s charter capital; afterward, their holding fell to roughly 3.26 million shares, or 0.638%.

Two of the funds involved — a Generali Vietnam life-insurance-linked vehicle and one of VinaCapital’s opportunity equity funds — exited their PNJ positions entirely. A third fund sold down to just 61 remaining shares. The two funds that kept the largest positions, VinaCapital’s Strategic Growth Equity Fund and its Modern Economy Equity Fund, still hold roughly 1.58 million and 1.68 million shares respectively.

The number that matters most, though, is the combined total. Once other entities in the VinaCapital ecosystem are included — a group holding roughly 22.3 million additional PNJ shares that did not sell — the full related-party stake fell from about 5.6% to approximately 4.9999%, or roughly 25.6 million shares. That’s just narrowly under the 5% line that defines a “major shareholder” in Vietnam.

The 5% Rule: How Vietnam Defines a “Major Shareholder”

Under Vietnam’s Securities Law, any investor or group of related investors holding 5% or more of a public company’s voting shares is classified as a “major shareholder” (cổ đông lớn). That status comes with an obligation: any subsequent change in ownership has to be disclosed to the State Securities Commission and the relevant stock exchange within a short window of the transaction.

Put simply:

Ownership ≥ 5% = Major Shareholder Status → Every Subsequent Trade Must Be Disclosed

Once a holder’s stake drops below that line, the disclosure requirement falls away — future buying or selling doesn’t need to be reported unless the stake climbs back above 5%. That’s precisely the position VinaCapital’s related-party group now sits in: with combined ownership at essentially 4.9999%, any further trimming — or just as easily, a modest add-back above 5% — could either go unreported or trigger fresh disclosure, depending on which direction it moves next.

PNJ Stock Price Timeline: The Last Two Weeks

Date	What Happened	PNJ Share Price
Late Jan 2026	Recent high	~VND85,000
Mar 20, 2026	VinaCapital group’s stake crosses 5%, becomes a major shareholder	~VND72,000
Jul 2, 2026	News breaks of P-Lab ex-director’s arrest in a diamond-smuggling probe	—
Jul 3, 2026	Shares hit the daily floor limit; over 11M shares unable to find buyers	-6.97%, VND58,700
Jul 6–7, 2026	Two more consecutive floor-limit sessions	Floor again
Jul 8, 2026	Shares rebound on record volume; VinaCapital group sells ~3.1M shares, stake falls to 4.9999%	+2.4%, VND52,000
Jul 9, 2026	Shares fall again	-3.85%
Jul 10, 2026	Shares fall further	-6.8%, VND46,600

Since the P-Lab story broke, PNJ shares have fallen roughly 26% over six trading sessions, erasing more than VND8.4 trillion in market capitalization — including a three-session run of consecutive floor-limit declines that alone wiped out over VND6,300 billion (about $255 million).

Breaking Down the P-Lab Diamond Smuggling Case

What P-Lab Is, and Why It Matters to PNJ

P-Lab — formally Công ty TNHH MTV Giám định PNJ, more commonly known as PNJ Lab — is a gemstone and diamond certification subsidiary wholly owned by PNJ. Established in 1998, it grew into the dominant player in Vietnam’s gem-testing market, at one point accounting for roughly 70% of all diamond and gemstone certification nationwide, and became the first lab in the country to earn ISO/IEC 17025 accreditation. P-Lab certifies more than 10,000 items a month, the majority of them diamonds, some worth millions of dollars, using testing equipment sourced from the Gemological Institute of America (GIA) and De Beers.

Because P-Lab is wholly owned by PNJ, its reputation is inseparable from its parent’s. A certification lab’s entire value proposition is trust — a piece of paper vouching for a diamond’s authenticity and grade. When that trust is called into question at a lab issuing certificates for roughly a third of Vietnam’s diamond and gemstone market, the reputational exposure doesn’t stay contained to the subsidiary.

The Allegations Against the Former P-Lab Director

On July 2, Thanh Hoa Provincial Police announced the arrest of Dang Ngoc Thao, P-Lab’s former director, as part of a broader investigation into a transnational diamond-smuggling ring. Authorities say the network ran roughly 141 smuggling trips between 2024 and mid-2026, bringing more than 28,000 diamonds into Vietnam from Hong Kong and generating an estimated VND280 billion (about $10.7 million) in turnover; 22 people have been prosecuted and roughly 1,100 diamonds seized so far.

The allegation specific to Thao is what rattled PNJ’s share price: investigators allege he used his gemological expertise to help source smuggled diamonds whose physical characteristics didn’t match their original GIA certification, then removed the laser-etched GIA serial numbers, re-engraved the stones with new P-Lab codes, and issued fresh certification documents that effectively legitimized the diamonds’ origin before they reached the market. This case remains under investigation, no court has issued a ruling, and the allegations against Thao are not proven facts.

PNJ’s Response So Far

PNJ has consistently characterized the case as a matter of individual legal responsibility rather than a company-wide failure, and says it is cooperating fully with investigators. The company set up a special monitoring task force at P-Lab, including two independent board members, and says it’s ready to help customers re-verify diamonds they’ve previously purchased, since certification records are retained and can be checked on request.

At an investor meeting on July 6, Chairwoman Cao Thi Ngoc Dung said PNJ’s diamonds are imported from Hong Kong and Thailand through fully compliant channels, and stressed that P-Lab’s role is limited to certification — it isn’t licensed to trade the diamonds it grades. She also noted that PNJ has long limited its exposure to large investment-grade diamonds, focusing instead on lifestyle jewelry.

Why This Matters for Investors

Subsidiary governance risk is real, not theoretical. A criminal case involving a wholly owned subsidiary’s former leadership hit PNJ’s market cap by more than VND6,300 billion in just three trading sessions — governance risk at a subsidiary doesn’t stay contained to the subsidiary’s own books.
Certification and trust-based businesses carry outsized reputational leverage. P-Lab’s value came from the market’s confidence in its stamp of approval; questioning that confidence affects every product carrying its paperwork, not just the diamonds under investigation.
Insider and institutional signals are pointing in different directions. While VinaCapital-linked funds were trimming exposure, the chairwoman’s brother separately registered to buy 300,000 PNJ shares — a reminder that different holders can read the same situation very differently.
Brokerages are already adjusting risk parameters. Several securities firms, including TCBS, pulled PNJ from their margin-eligible lists or cut lending ratios starting July 9 — a practical signal of how professional risk desks are treating the stock in the near term.

What to Watch Next

The shareholder vote on the buyback. PNJ’s board has fast-tracked a written consent process for a treasury share buyback aimed at supporting the stock and shareholder value; watch for the outcome and the scale of any repurchase.
Progress in the criminal investigation. Any formal charges, court proceedings, or expansion of the case to additional individuals or entities could move sentiment further in either direction.
PNJ’s Q3 2026 results. Management has so far reaffirmed its full-year targets — VND48,660 billion in revenue and VND3,409 billion in after-tax profit — but SSI has already trimmed its own 2026 profit estimate to VND3.333 trillion, arguing it’s too early to set a reliable valuation while the case is unresolved.
Whether the 5% threshold gets crossed again. With VinaCapital’s related-party group sitting at almost exactly 4.9999%, any further move is worth tracking, alongside PNJ’s other large holders, including Dragon Capital (around 6%) and T. Rowe Price (around 5.79%).

Key Numbers to Watch

The 4.9999% Line

It’s hard to read VinaCapital’s related-party stake landing at essentially 4.9999% as a coincidence. Whether the funds specifically targeted the threshold or simply sold what they judged appropriate and happened to land just under it, the practical effect is the same: no further disclosure obligation unless the group’s ownership climbs back above 5%. For outside investors, that means one source of visibility into a major holder’s activity has, for now, gone dark.

The Treasury Buyback Mechanics

PNJ shareholders had already approved a general buyback mandate back in April 2026, to be used “at an appropriate time.” The P-Lab crisis appears to be that moment: on July 8, the board fast-tracked a written shareholder consent process for a new repurchase, while also moving to sell its existing 169,559 treasury shares first — a procedural step required under Vietnamese regulations before a fresh buyback can proceed, expected to unfold over the third quarter of 2026.

Diamond Revenue Exposure

Diamond-related products make up roughly a third of PNJ’s jewelry revenue — about 10% from loose diamonds and 23% from diamond-set jewelry. That’s the segment most directly exposed to any lasting damage to P-Lab’s credibility, which is part of why analysts are watching the certification story as closely as the criminal case itself.

Conclusion

VinaCapital’s exit from “major shareholder” status is, on its own, a fairly narrow regulatory event — a related-party group crossing a specific ownership line. What makes it notable is the context: it happened on the single best trading day PNJ has had since its certification subsidiary became the center of a criminal investigation, right as the company itself moved quickly to shore up confidence with a buyback plan. Neither fact proves anything about where PNJ shares go from here. But together, they capture how differently professional money and company insiders can read the same moment.

Disclaimer: This article is for informational and educational purposes only and does not constitute financial or investment advice. The criminal case described here remains under investigation; the allegations against the individual named are not proven facts, and no court has issued a ruling. Vietnamese stock prices and ownership percentages can change quickly — always verify current data before making any investment decision. For personalized guidance, Finance-Solutes.com’s free courses and expert advisors are available to help you evaluate developments like this one in the context of your own portfolio.

Sources: State Securities Commission of Vietnam / HOSE disclosure filings, as reported by VnExpress and VnExpress International

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