Plexus Corp. (PLXS)

How it makes money

Revenue comes from making and shipping products for customers. Most work is 'turnkey': Plexus buys the components itself, builds the product and bills a price that covers materials plus its own value added, so the bill of materials flows through the income statement and keeps reported margins structurally thin. A smaller share is 'consignment', where the customer supplies the parts and Plexus charges only for labour and services. The company also earns fees for design, engineering and sustaining services (repair, refurbishment, spare parts), which usually come before and after the manufacturing phase of a programme. The 10-K states that Plexus generally does not obtain firm, long-term purchase commitments: customers issue forecasts and short-horizon orders, Plexus finances the material purchase in advance, and many contracts allow prices to be renegotiated periodically — often quarterly — when component costs move.

Revenue by segment

Contract manufacturing is a competitive, low-margin business and Plexus openly says it faces many rivals, some far larger. What softens that is the kind of work it takes on: a surgical instrument or an avionics box is qualified with the regulator at a named site, under FDA, aerospace and defence quality regimes, and often after Plexus has helped design it. Moving such a programme to another supplier means requalification, revalidation and schedule risk, so programmes tend to stay put for the life of the product. The advantage protects existing programmes rather than pricing power on new ones, which is why it is better read as narrow than wide.

Demand is driven by customers' new product launches and by their capital and equipment spending, so it arrives in programme ramps rather than as a steady flow. The mix splits the cycle: healthcare and life-science instruments (40% of fiscal 2025 sales) hold up reasonably well through downturns, while industrial work (43%) — factory automation, semiconductor capital equipment, test and measurement — swings with industrial capex and the semiconductor cycle, and aerospace/defence (17%) follows long, slow-moving programme and budget schedules. Because Plexus buys materials ahead of forecasts, a slowdown shows up first as inventory and unabsorbed capacity, and only then in sales.

Key risks

• No firm long-term purchase commitments — Plexus discloses that it generally works from customer forecasts rather than binding long-term orders. Customers can cancel, delay or reduce volumes, and the company may be left with inventory and capacity built against a forecast that did not materialise.
• Concentration in a limited number of customers and sectors — A large slice of revenue comes from a small group of customers and from three market sectors. The loss of a major customer, or a downturn confined to one sector, would hit results even though no single customer reached 10% of sales in fiscal 2025.
• Component availability, supplier delays and price volatility — Because Plexus buys the materials on turnkey programmes, shortages, allocation or sudden price increases can delay shipments and squeeze margins, especially where contract pricing can only be adjusted at set intervals.
• Inventory build and obsolescence — The company carries significant inventory purchased ahead of customer demand. If a programme is cancelled, redesigned or ramps more slowly than forecast, that inventory can become excess or obsolete and require write-downs.
• Competitive and pricing pressure — Plexus competes with other electronics manufacturing services providers and with customers' own in-house operations. Competitors with greater scale or lower cost structures can force price concessions in a business that already runs on thin operating margins.
• Regulatory burden in medical, aerospace and defence work — Facilities serving these sectors are subject to quality-system, export-control and government-contracting rules. Failing an audit, losing a certification or breaching export rules could interrupt production and expose the company to penalties.
• Multinational operations and geopolitical exposure — Manufacturing is spread across the Americas, Asia-Pacific and EMEA, which exposes Plexus to tariffs and trade restrictions, currency movements, labour cost inflation and political instability in the countries where it builds.
• Dependence on customers' technology and product cycles — Plexus' revenue follows products it does not own. If a customer's product loses its market, is superseded by new technology or never reaches volume, the associated programme revenue disappears with it.

Top customers account for 49.1% of revenue

The 10-K states that the ten largest customers accounted for 49.1% of net sales in fiscal 2025, up from 47.8% in fiscal 2024, and that no single customer represented more than 10% of sales in either year. So roughly half the business rests on ten relationships out of about 190 customers — concentrated, but without one name whose departure would dominate the rest.