Latest close
$352.21
As of Oct 19, 2026
| Fund | Portfolio weight | Shares | Change vs prev. quarter |
|---|---|---|---|
| Jericho Capital Asset Management | 3.40% | 644,764 | ADDED (+10.9%) |
| Whale Rock Capital Management | 2.05% | 400,687 | TRIMMED (-2.7%) |
| Samlyn Capital | 0.91% | 87,577 | TRIMMED (-53.7%) |
| Atalanta Sosnoff Capital | 0.45% | 39,864 | NEW |
| Tortoise Capital Advisors | 0.21% | 31,574 | ADDED (+13.1%) |
| Winslow Capital Management | 0.07% | 31,678 | NEW |
| Maverick Capital | 0.01% | 1,882 | NEW |
Source: SEC Form 13F filings for the quarter ended Jun 30, 2026. Change labels compare each fund’s 2026 Q2 filing with its previous filing. 13F filings cover long positions only and arrive up to 45 days after quarter-end. Fund counts here aggregate every share class mapped to this ticker; research headlines cite filer counts as they stood at publication, so a count here can differ from a headline by a holder (see Methodology, "How holder counts are counted").
Filing season: the Q3 2026 13F tracker follows every tracked fund’s filing for the quarter ended Sep 30, 2026, with its biggest buys and sells.
| Institutions holding | 1,856 of 8,857 filers |
| Long-only filers among them | 1,843 |
| Change vs 2026 Q1 | +454 net · 1,555 entered · 1,101 exited |
| Shares reported, all filers | 321,314,544 |
| Reported value, all filers | $231.1B |
Source: SEC Form 13F data sets — every filer's latest report for the quarter ended Jun 30, 2026, not just the tracked funds above; changes compare with the quarter ended Mar 31, 2026. Share counts and values are summed as reported in the filings (a small number of filers report values in thousands of dollars, so value totals are as-filed sums).
| Exchange | Nasdaq |
| Industry | Computer Storage Devices (SIC 3572) |
| Revenue · FY2026 | $12.9B |
| Net income · FY2026 | $9.4B |
| Total assets · FY2026 | $13.9B |
| Shares outstanding | 360,540,944 |
| Market cap (at latest close) | $127.0B |
Source: SEC EDGAR company filings (submissions and company facts), collected Oct 7, 2026. Shares outstanding as reported Aug 7, 2026.
| Shares short · Sep 15, 2026 | 17,280,387 |
| Share of shares outstanding | 4.79% |
| Days to cover | 3.13 |
Shares short at recent settlements — Jun 30, 2026: 22.4M · Jul 15, 2026: 23.3M · Jul 31, 2026: 24.6M · Aug 14, 2026: 20.3M · Aug 31, 2026: 19.9M · Sep 15, 2026: 17.3M.
Source: FINRA Equity Short Interest (biweekly settlement data). Shares outstanding from SEC filings as of Aug 7, 2026.
| Shares failed to deliver · Sep 15, 2026 | 0 |
| Share of shares outstanding | 0.00% |
| Fails as a share of short interest · Sep 15, 2026 | 0.0% |
Fails to deliver at recent settlements — Jun 30, 2026: 95K · Jul 15, 2026: 0 · Jul 31, 2026: 0 · Aug 14, 2026: 0 · Aug 31, 2026: 0 · Sep 15, 2026: 0.
Source: SEC Fails-to-Deliver data (semi-monthly files, published about two weeks after each settlement date). Each figure is the balance of shares not yet delivered on that date; a stock absent from that date’s file counts as zero. See our research on whether fails to deliver predict returns. Shares outstanding from SEC filings as of Aug 7, 2026.
0 insiders bought on the open market in the last 90 days (0 purchases, $0), against 48 sales by 5 insiders ($15.3M).
Source: SEC Form 4 filings, as of Oct 20, 2026. Open-market transactions only.
1 member of Congress reported buying (1 purchase vs 0 sales). Bought by Democrats. Latest buy: Jul 17, 2026.
Source: U.S. House Clerk and U.S. Senate eFD STOCK Act periodic transaction reports, as of Oct 3, 2026. Reported amounts are ranges, and reports can arrive up to 45 days after the trade.
Politicians
· Bought by Members — Last 6 months: bought by a member of the U.S. Congress
Financial Screens
· Piotroski — Financial health improved over the past year
· Lynch PEG — Cheap against its growth rate
· Neff Total Return Ratio — Growth plus dividends divided by P/E is high
· Gross Profitability (Novy-Marx) — High gross profit relative to total assets
Red Flags
· Excess Accruals (Sloan) — Sloan accruals ratio beyond ±25%
Key figures
· Piotroski — F-score: 7 · Return on assets: 68.0% · Operating cash flow: $3.9B
· Lynch PEG — P/E: 16.70 · 5-yr EPS growth: 55.6% · PEG: 0.30
· Neff Total Return Ratio — EPS growth: 55.6% · Dividend yield: 0.1% · P/E: 16.70 · Neff ratio: 3.34
· Gross Profitability (Novy-Marx) — Gross profit / assets: 45.5% · Gross margin: 48.9%
· Bought by Members — Members buying: 1 · Buy txns: 1 · Sell txns: 0 · Latest buy: Jul 17, 2026
· Excess Accruals (Sloan) — Accruals ratio: 42.7% · Net income: $9.4B · Operating cash flow: $3.9B · Investing cash flow: $-429.0M
Financial screens are computed from SEC company financial statements; red-flag models are screens, not verdicts — see Methodology.
| 13F signal (2021 Q3 – 2026 Q1) | Events | Win rate | Avg return | SPY | Excess |
|---|---|---|---|---|---|
| Share count tripled (3x) | 2 | 50.0% | +1.2% | +0.9% | +0.3% |
Measured from SEC 13F filings: entry at the close on the first trading day after each quarter’s filing deadline, exit one quarter later on the same rule, dividend-adjusted closes. Past records do not guarantee future results — see Track Record and Methodology.
Also held by the tracked funds that hold WDC: NVIDIA CORP (NVDA) · MICRON TECHNOLOGY INC (MU) · AMAZON COM INC (AMZN) · MICROSOFT CORP (MSFT) · Meta Platforms, Inc. (META) · APPLIED MATERIALS INC /DE (AMAT) · Lumentum Holdings Inc. (LITE) · Snowflake Inc. (SNOW) · Alphabet Inc. (GOOGL) · Alphabet Inc. (GOOG).
Filings audit: every filing lens on WESTERN DIGITAL CORP (WDC), scored — GetCoattail Research.
Open the interactive tool →Live screens, charts and backtests for every tracked stock, fund and signal — free, no sign-up.