The divergence between TTM P/E of 13.86 and forward P/E of 34.39 is the single most important valuation signal, because net margins of 96.0% in 2026Q3 and 85.3% in 2026Q4—versus operating margins of 35.7% and 41.7% in the same periods—indicate roughly $2B and $1.6B in non-operating gains respectively that materially inflated TTM EPS. PEG of 0.25, versus STX's 2.16 and MU's 4.41, appears to price in continued acceleration that may be difficult to sustain if AI-driven storage demand decelerates. EV/EBITDA of 24.65 sits below STX (32.78) and MU (54.70) but above SNDK (13.67), suggesting the market still applies a conglomerate discount to WDC's dual-technology heritage despite the completed SanDisk separation. Investors should treat the 13.86 TTM P/E as unreliable and anchor on the 34.39 forward P/E and P/FCF of 33.74, both of which better reflect underlying manufacturing earnings power in a normalized pricing environment.

The operating margin trajectory from 19.9% (2025Q2) to 46.7% (2027Q1) demonstrates exceptional fixed-cost operating leverage, as quarterly R&D and SG&A remained roughly flat while operating income grew nearly sixfold—a pattern characteristic of a high-fixed-cost manufacturer operating at peak utilization. The FCF margin recovery from -2.8% (2025Q1) to 31.4% (2027Q1) confirms that reported margin expansion is being converted into actual cash generation, though the FCF trajectory trails the sharper operating margin surge, suggesting working capital absorption is partially offsetting accounting profitability. Based on the company's structural cost analysis, the 57.8% gross margin appears to represent cycle-peak territory; the 2024Q4 trough of 47.0% gross margin and 1.9% net margin serves as a reminder that NAND and HDD pricing can normalize rapidly when industry inventory cycles turn. The 40.6% net margin in 2027Q1, while lower than the 85-96% peaks in 2026, may represent a more sustainable normalized level as non-operating distortions wash out of the trailing figures.

The ROIC improvement from 1.5% to 17.9% over eight quarters represents genuine value creation, with roughly two-thirds attributable to margin expansion and one-third to the asset turnover improvement. However, the turnover gain must be interpreted cautiously, as total assets contracted approximately 44% from $25.5B to $14.2B primarily due to the SanDisk separation, mechanically inflating the turnover ratio without equivalent improvement in underlying operating efficiency. ROE's compression from 37.7% (2026Q3) to 19.5% (2027Q1) appears to reflect retained earnings growing from $521M to $9.3B rather than a decline in earning power, making ROE a less reliable comparator than ROIC for this period. Against peers, WDC's 17.9% ROIC sits above MU's 13.2% but well below the reported 80.0% (STX) and 87.9% (SNDK) figures, though those peer ROIC readings appear anomalous and warrant verification given their elevated P/B multiples and post-restructuring equity bases.

The DSO improvement from 69 days to 44 days appears consistent with a shift toward cloud and enterprise customers with faster payment profiles, versus the client and consumer channels that historically drove slower collections. DPO has remained relatively stable in the 84-89 day range over the last six quarters, indicating the working capital gains are being driven by the asset side (receivables and inventory) rather than supplier financing stretch, which suggests the improvement is operationally genuine rather than a financial engineering artifact. Asset turnover improvement from 0.08 to 0.31 must be viewed in the context of the structural balance sheet contraction from the separation, though the underlying 4x improvement in absolute turnover days on receivables and inventory points to real execution gains. Investors should monitor whether the current 81-day DIO can be sustained if NAND pricing normalizes and enterprise customers allow inventory to rebuild, as the prior 197-day peak in 2024Q4 would represent a significant cash drag if repeated.

The deleveraging trajectory from D/E of 0.96 in 2025Q4 to 0.08 in 2027Q1, combined with debt/EBITDA falling from 6.63x to 0.37x, effectively eliminates near-term refinancing risk and represents a dramatic reversal from the SanDisk acquisition period when leverage constrained strategic flexibility. Interest coverage improvement from a negative reading (-0.88) in 2024Q4 to 185.27x in 2027Q1 reflects both the deleveraging and the operating income surge, and while the recent moderation from 390.75x to 185.27x appears to reflect higher absolute interest expense or a modest EBITDA reduction, both readings are exceptionally comfortable. Compared to Seagate's 1.65 D/E and Micron's 0.28 D/E, WDC's 0.08 position is meaningfully stronger and provides capacity for either M&A optionality or further shareholder returns during the announced strategic separation. The primary consideration is whether management will deploy this excess capacity into capital-intensive HAMR technology transitions, share repurchases exceeding the current $3.8B ten-quarter pace, or bolt-on acquisitions in adjacent storage technologies.