Longleaf Partners Global Fund Q3 2026 Portfolio Review

Regeneron reported solid results, with Dupixent growth exceeding the author’s and market expectations. Abbott slightly missed earnings estimates in the first part of the year, before the author invested, amid integration of its Exact Sciences acquisition and turmoil in medtech and infant nutrition. People Inc. and MGM Resorts detracted from quarterly performance.

Analysis

The clearest signal is a difference in earnings visibility, not a broad healthcare call. Dupixent’s growth supports the durability of Regeneron’s product outlook, but the investable question is how much of that upside accrues to Regeneron versus Sanofi and whether growth persists as competition and launch expectations evolve. Treat the result as a reason to favor REGN on weakness, not to chase without valuation and product-level contribution data.

For Abbott, integration adds execution risk on top of unrelated medtech and infant-nutrition volatility. The second-order risk is that management attention and capital allocation are judged against the acquired Exact Sciences business before its contribution is independently clear; evaluate the combined company rather than treating EXAS as a separate exposure. Over the next 1–3 months, watch integration updates, guidance, and segment trends. Over 6–18 months, the thesis turns on whether acquired growth and synergies offset disruption in legacy segments. A further guidance cut or worsening segment trends would falsify a stabilization view.

MGM’s quarter-level detractor status alone does not establish deteriorating fundamentals. Its sensitivity to discretionary travel and entertainment spend makes consumer data and property-level operating trends more relevant than this isolated portfolio outcome. No strong directional signal is supported for MGM or People Inc. without underlying operating metrics.

Key Decisions for Investors

• REGN: Prefer adding on weakness rather than chasing the earnings response. Verify Dupixent growth, forward guidance, and Regeneron’s economic contribution alongside Sanofi; reassess if product growth decelerates or guidance fails to convert into improved outlook.
• ABT: Stay cautious pending evidence that integration is progressing without further deterioration in legacy segments. Track organic growth, segment guidance, and acquisition-related costs at the next update; avoid treating EXAS as a standalone catalyst absent deal-status and security details.
• MGM: No trade from the reported detractor status alone. Watch consumer-spending data and property-level operating metrics; a sustained deterioration would strengthen a cautious view, while resilient operating trends would argue against extrapolating one quarter.
• Portfolio stance: The article supports selective healthcare differentiation, not a sector-wide position. Revisit sizing after current valuation, consensus expectations, and company guidance are checked.