These Were the S&P 500's Top Performers in 2025. Are They Still Good Buys in 2026?

Memory and storage names outperformed in 2025 as AI-driven demand lifted Sandisk (+559%), Western Digital (+238%) and Micron (+198%). Sandisk reported revenue of $2.3 billion for the quarter ended Oct. 3, 2025 (up 23% YoY) but saw net income fall 47% and trades at a forward P/E of ~20 with a $40 billion market cap. Western Digital posted $2.8 billion in revenue (up 27%) and profits rising from $493 million to nearly $1.2 billion, trading at a forward P/E of ~25. Micron, exiting its Crucial consumer business to focus on strategic customers, grew 57% in its quarter ended Nov. 27, 2025, with ~40% margins and a forward P/E of ~10, positioning it as the most attractively valued of the three.

Analysis

Market structure: The AI-driven surge shifted near-term winners to memory/storage suppliers (MU, WDC, SNDK) and capex equipment vendors (AMAT/LRCX exposure). Hyperscalers and enterprise AI infrastructure buyers capture value through scale, while consumer/retail SSD vendors and low-end NAND suppliers face margin pressure. Short-term pricing power is strong for DRAM/NAND (lead times 6–12 months), but history shows rapid mean reversion if orders slow.

Risk assessment: Key tail risks are a 30%-plus pullback in hyperscaler AI orders, new US/China export controls on advanced nodes, or a rapid inventory glut that compresses DRAM/NAND prices by 40–60%. Immediate (days-weeks) risk is momentum reversal; short-term (1–3 months) hinges on quarterly guidance; long-term (12–36 months) depends on capex cycles and fab buildouts. Hidden dependencies: SNDK’s concentration with five hyperscalers and Sandisk’s interest-bearing liabilities; Micron’s margin sustainability relies on enterprise/server DRAM demand.

Trade implications: Tactical allocation: overweight MU (value + high margins) and selective WDC exposure for stability; avoid unilateral long SNDK without hedges. Use 3–6 month call spreads on MU to capture asymmetric upside, sell covered calls on WDC to monetize rallies, and buy 3-month 10–15% OTM puts on SNDK or short SNDK at 50–75% sizing vs MU long. Rotate 5–10% from NVDA/concentrated AI software into memory and equipment suppliers over the next 4–12 weeks.

Contrarian angles: Consensus underprices cyclical downside and supplier concentration risk—SNDK’s 559% run could be most exposed to mean reversion. MU may be underowned given forward P/E ~10 and 40% margins, suggesting a durable relative value; conversely, a repeat of 2016–18 memory bust remains possible if hyperscalers delay spending, forcing consolidation or rapid price declines.

Key Decisions for Investors

• Establish a 2–3% portfolio long position in MU (Micron) within 2 weeks; add up to +1% on any pullback ≥10%; target horizon 12–24 months, take profits on +50% or if forward P/E >15 or gross margin falls by >500bps.
• Establish a 1–2% long position in WDC (Western Digital) and sell 1–2% covered calls (3-month) to collect premium; trim position by 50% if revenue guidance misses by >5% QoQ or net income margin contracts by >300bps.
• Avoid new outright long exposure to SNDK (Sandisk); instead size a hedge/short at 0.75x your MU long via either 3-month 10–15% OTM puts or a short position if borrow cost <3%. Close hedge if SNDK drops >30% or if company reduces hyperscaler concentration to <3 customers.
• Implement a pair trade: Long MU / Short SNDK sized 1:0.75 to capture relative value; monitor hyperscaler capex guidance and company inventory-days disclosures over next 30–60 days—if combined inventory rises >15% QoQ, reduce gross exposure by half.
• Rotate 5–10% of technology exposure from NVDA-sized crowd to memory supply chain (MU, WDC) and equipment suppliers (AMAT, LRCX) over 4–12 weeks to capture capex ripple; reassess after next quarterly earnings cycle.