Build a Portfolio Watchlist of Companies You Do Not Own
Published August 8, 2026
Altsets
Research by Altsets Research
Use weighted customer exposure and evidence coverage to prioritize non-owned companies for earnings monitoring without inventing a universal network risk score.
Dataset reference:Altsets supply chain relationships dataset covers 115k+ entities, 550k+ relationships, and history since 2006 across the full dataset; individual analyses use a narrower scope.
Key findings
- An illustrative 8% Micron and 2% SK hynix allocation gives Nvidia a 1.9672% customer-revenue exposure indicator; Micron contributes more because its holding weight is larger.
- Customer and supplier monitoring should remain separate lists because revenue dependence and procurement cost share measure different financial objects.
- A watchlist should show exposure contributions, missing coverage, next catalyst and product relevance rather than only a node-centrality score.
The most useful outside-company watchlist starts with what the account owns. A large customer can deserve an earnings alert even if its stock has zero account weight. A supplier can deserve a disruption alert for the same reason, through a different financial channel.
Consider a hypothetical account with 8% Micron and 2% SK hynix, with the rest left unspecified. Nvidia appears as a customer of both in Altsets, at 17.62% and 27.88% of the respective supplier revenue bases. Which holding makes Nvidia worth watching most closely?
Holding size changes the answer
| Route to the outside company | Assumed account weight | Customer revenue share | Weighted contribution |
|---|---|---|---|
| Micron → Nvidia | 8% | 17.62% | 1.4096% |
| SK hynix → Nvidia | 2% | 27.88% | 0.5576% |
| Selected customer routes | 10% | — | 1.9672% |
SK hynix has the larger company-level Nvidia concentration, but Micron contributes about 71.66% of this account's selected exposure indicator because the Micron position is four times larger. Ranking counterparties by their largest relationship percentage alone would miss the account's actual monitoring priority.
The indicator is a weighted commercial-exposure measure. It neither forecasts losses nor describes a hidden Nvidia shareholding. The unspecified rest of the account prevents a claim that Nvidia is the account's largest outside dependency.
A watchlist entry should explain the alert
For Nvidia, the alert should name the channel: memory purchases, product timing or supplier qualification that might alter sales at the two owned suppliers. A general Nvidia leadership or software headline may not affect that channel.
A useful watchlist record contains the outside entity, each exposed holding, the contribution shown above, the observation date, product relevance, evidence gaps and the next event worth monitoring. The exposure indicator orders the review; the event's connection to the products determines whether the alert is actionable.
I would use this list to allocate research time before using it to change positions. An important outside company is a reason to read the right earnings call, not an instruction to buy or sell the customer.
Keep the procurement list separate
A supplier watchlist uses the holding's cost share, with additional facility and substitution evidence. Averaging those cost shares together with customer revenue shares would make the final rank difficult to interpret. A company can appear on both lists, but the explanation should preserve both routes.
Structural edges without percentages belong in a coverage section. A counterparty with many unmeasured links may warrant investigation; giving those links zero weight would suppress precisely the uncertainty the watchlist should expose.
The list can change without a trade
Holding weights can remain fixed while customer shares change, a product relationship ends or a supplier becomes relevant to a new platform. Save both the holdings and the relationship snapshot when generating an alert perimeter. That allows an analyst to distinguish a portfolio decision from a change in the businesses beneath it.
The shared-customer screen discovers common buyers. The shared-supplier analysis handles common inputs. Point-in-time backtest construction explains how to preserve historical monitoring universes.
Sources
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Cite this research
Altsets Research. "Build a Portfolio Watchlist of Companies You Do Not Own." Published August 8, 2026. https://www.altsets.com/research/portfolio-most-important-external-company