Citadel Advisors and Millennium Management made notable additions to their Fabrinet (NYSE:FN) positions during the second quarter, according to the latest Form 13F filings.

The timing is striking: weeks later, the optical manufacturing specialist reported record financial results, revealed an increasingly diversified customer base led by Cisco Systems, Inc. (NASDAQ:CSCO), Nvidia Corp (NASDAQ:NVDA), Amazon.com Inc (NASDAQ:AMZN) and Nokia Corp (NYSE:NOK), and told investors there was “no end in sight” to customer demand—highlighting why the company has become an increasingly important player in AI infrastructure.

Citadel Advisors and Millennium Significantly Expanded Their Fabrinet Positions

The latest Form 13F filings for the quarter ended June 30 show Citadel Advisors and Millennium Management substantially increased their exposure to Fabrinet.

• Citadel Advisors made the biggest move. Its disclosed common stock position jumped from 4,963 shares in the first quarter to 151,705 shares in the second quarter, an increase of nearly 2,957%. The reported value of the holding climbed from $2.6 million to $85.3 million.
• Millennium also significantly expanded its investment, increasing its common stock holdings from 61,692 shares to 164,313 shares, while the reported value of the position rose from $32.2 million to $92.4 million.
• Another notable institutional investor, AQR Capital Management, also added to its position during the quarter, increasing its holdings from 71,849 shares to 79,795 shares, with the reported value rising from $37.1 million to $44.1 million.

Form 13F filings disclose institutional holdings at quarter-end rather than the reasons behind investment decisions. Still, the portfolio changes coincided with one of Fabrinet’s strongest operating quarters to date.

Also, it’s worth noting that 13F filings are a snapshot of holdings as of June 30, 2026, and don’t reflect any portfolio changes that may have been made by any of these hedge funds after the quarter ended.

Fabrinet’s Customer List Reflects a Broader AI Infrastructure Story

The company’s latest earnings suggested its AI opportunity is becoming increasingly diversified.

Chief Financial Officer Csaba Sverha told investors:

“In 2026, we continued to diversify our customer base, with four customers representing 10% or more of total revenue. These were Cisco at 20%, Nvidia at 16%, Nokia at 11%, and Amazon at 11% of total revenue.”

The disclosure stands out because it shows Fabrinet generating meaningful revenue from networking, cloud and semiconductor leaders rather than relying on a single AI customer. That’s our inference based on the customer mix; management simply highlighted the diversification.

The company also reported that data center applications accounted for 51% of fiscal 2026 revenue, underscoring the growing importance of AI infrastructure to its business.

Management Says AI Demand Shows ‘No End in Sight’

Beyond the financial results, management struck an unusually confident tone about the demand environment.

Chief Executive Officer Seamus Grady said:

“Demand from these markets continues to increase, which makes us optimistic about the long-term durability of these trends.”

Later, when asked about customer demand, he added:

“There looks to be, you know, no end in sight to the demand from the customers.”

Management also pointed to continued momentum across data center interconnect (DCI), high-performance computing (HPC) and optical transceivers, suggesting AI-related demand remains broad-based rather than dependent on a single product cycle.

What Fabrinet Investors Should Watch Next

The latest 13F filings don’t reveal why Citadel Advisors, Millennium or AQR increased their Fabrinet positions, nor do they capture any portfolio changes after June 30.

What they do show is that several sophisticated investors increased exposure ahead of an earnings report that reinforced Fabrinet’s role in AI infrastructure through a diversified customer base, record operating performance and confident management commentary.

For investors, the next key question is whether those fundamentals continue to support the company’s premium valuation as AI networking deployments scale and new customer programs move into production.

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