BlackRock the silent 15%-stake holder, T. Rowe halved, Fidelity bulked up, Newtyn accumulated through the drawdown. A reading of the proxy, the 13F-HR filings, and the Schedule 13Gs filed around them.
QuidelOrtho's 2026 proxy statement, filed April 27, sets a record date of April 20 and an annual meeting for June 16. Between those dates, the institutions disclosing 5% or greater positions in the company filed a cluster of Schedule 13Gs and amendments that — combined with the Q1 2026 13F-HR filings — describe a meaningful reshuffling of the shareholder base over the past three quarters.
The largest QDEL holder is BlackRock, Inc. at 10,449,127 shares (15.34% as of 3/31/2026, per the 13F-HR filed 5/13/2026) — a position built largely through passive vehicles (the iShares Core S&P Small-Cap ETF sleeve, plus various active mandates) and broadly accumulated through 2025 from 8.19M at Q1'25 to 10.45M at Q1'26. BlackRock does not file 13G amendments on a quarterly cadence at this level, so the 13F is the only public window.
The most consequential active move belongs to T. Rowe Price Investment Management, which entered 2025 as a top holder at 16.7% and ended Q1 2026 at 8.3% — a position roughly halved across four quarters, with the cut concentrated in Q4 2025 (a single-quarter sale of 6.07M shares per 13F data). The shares released found receptive buyers. FMR LLC (Fidelity) reported 6,591,152 shares (9.68%) at 3/31/2026 — then added another 1.26M to reach 7,852,322 shares (11.5%) by 4/30/2026. Newtyn Management, a New York value shop, crossed the 5% threshold in late 2025 and continued adding through the Q1 2026 weakness, ending Q1 at 6.7% and reaching 7.8% by April 29.
The Carlyle Group — Ortho Clinical Diagnostics' former private equity owner — completed its full exit in November 2024 via a Goldman-led secondary offering of 8.26 million shares at $35.31. That clearing event preceded, and arguably enabled, the holder rotation that played out across 2025.
A January 12, 2026 internal realignment at The Vanguard Group complicated the comparison: TVG amended its 13G to zero shares and now reports through disaggregated affiliates (Vanguard Portfolio Management LLC, Vanguard Capital Management LLC), each filing separately. Combined Vanguard-managed exposure looks broadly comparable to the pre-realignment ~10% block, but the headline numbers across filers are now smaller.
Estimated average buy prices are derived from each holder's documented build history. Only Rubric Capital's $49.72 average is independently disclosed — the rest are reasoned estimates. Adjust the current price below to see the model respond.
| Rank | Holder | Shares | % Class | Est. Avg Buy ($) |
Cost Basis ($M) |
Current Value ($M) |
Unrealized P&L ($M) |
P&L % | Filing |
|---|---|---|---|---|---|---|---|---|---|
| I | BlackRock, Inc. — Q1 2026 | 10,449,127 | 15.34% | $45.00 | — | — | — | — | Form 13F-HR filed 5/13/26 as of 3/31/26 |
| II | FMR LLC (Fidelity) — Q1 2026 | 6,591,152 | 9.68% | $28.00 | — | — | — | — | SC 13G/A filed 5/5/26 as of 3/31/26 |
| III | T. Rowe Price Investment Mgmt | 5,629,965 | 8.3% | $52.00 | — | — | — | — | SC 13G/A 4/8/2026 |
| IV | Newtyn Management LLC — Q1 2026 | 4,558,472 | 6.7% | $28.00 | — | — | — | — | SC 13G filed 4/30/26 as of 3/31/26 |
| V | Vanguard Portfolio Mgmt LLC | 4,088,168 | 6.0% | $42.00 | — | — | — | — | SC 13G 4/29/2026 |
| VI | Vanguard Capital Mgmt LLC | 3,572,563 | 5.2% | $42.00 | — | — | — | — | SC 13G 5/6/2026 |
| VII | Invesco Ltd. (now <5%) | 3,117,469 | 4.6% | $43.00 | — | — | — | — | SC 13G/A 5/6/2026 |
| Aggregate 5%+ at Q1 2026 (3/31) | 38,006,916 | 55.8% | — | — | — | — | — |
Themed view of the most consequential changes in the QDEL holder base. Direction and magnitude in monospace; commentary in serif. Each card represents one well-documented narrative thread visible in the filings.
Per 13F-HR filed 5/13/2026: BlackRock holds 10,449,127 shares (15.34%) at 3/31/2026 — ahead of FMR by ~3.86M shares. Q1'25 8.19M → Q2'25 10.22M → Q1'26 10.45M, an accumulation of ~2.26M over the year. Largely passive (IJR sleeve + active mandates). Doesn't file 13G amendments at this cadence — the 13F is the only window.
From 11.45M (Q1 2025) → 5.63M (Q1 2026). Position cut by ~51%. Likely driven by 2025 negative analyst revisions (UBS PT to $26, JPMorgan to $25). The remaining shares are the oldest, highest-cost tranche of the original build.
From 2.62M (Q2 2025) to 6.59M / 9.68% (Q1 2026, 3/31), then to 7.85M / 11.5% by 4/30/2026 (+1.26M in April alone). Multi-quarter accumulator; pace accelerated post-Q1 close.
~1.7M (pre-Q3'25) → 2.7M (Q3'25) → 4.56M (Q1'26) → 5.3M (Apr 29, 2026). Crossed 5% in late 2025 and kept buying through the Q1 2026 drawdown — a value-style accumulation pattern.
From 6.14M (Q1 2025) → 4.64M (Q2 2025). Disclosed average cost $49.72/share against ~$11.50 current — a sitting paper loss north of 75%.
From 3.45M / 5.1% (Q4'24) → 3.12M / 4.6% (Q1'26). The 13G/A is the exit notice — required when a holder drops below 5%. Position still material, but reporting cadence loosens.
TVG's January 12, 2026 internal realignment, citing SEC Release 34-39538, disaggregates affiliate reporting. TVG itself reports 0 shares; affiliates file separately. Vanguard-managed exposure broadly stable — but headline numbers across filers are now smaller.
Completed November 21, 2024 via $291.7M Goldman-led secondary offering at $35.31/share. Removed the ~12% PE overhang and ended board rights — the catalyst that opened up the subsequent holder rotation.
Q1 2026 revenue down 10.5% YoY (Point-of-Care −34%, Labs −5%); company cut full-year 2026 guidance May 5, 2026. Value-style holders (Newtyn) still adding; growth/momentum holders (T. Rowe) exiting.
Q1 2026 13F-only positions just below the 5% threshold. Dimensional 3,048,768 (4.48%) — up from Q2'25 2.41M, continued passive accumulation. American Century 2,856,132 (4.19%) — up sharply from Q3'25 1.59M, rebuilt through the drawdown. Rubric 3,306,281 (4.86%) — continued trim from Q4'25 ~3.77M, now below 5% reporting threshold. Combined 9.21M shares (13.5%).
Q1 2025 included as context; the three most recent quarters (Q3 2025, Q4 2025, Q1 2026) are the focus. Em-dash indicates either no 13F filing for that quarter or aggregator data not pulled to this level of granularity.
| Holder | Filing Type | Q1 2025 | Q2 2025 | Q3 2025 | Q4 2025 | Q1 2026 | Δ Shares (Q1'26 vs Q3'25) |
Δ % |
|---|---|---|---|---|---|---|---|---|
| FMR LLC (Fidelity) | SC 13G/A + 13F | — | 2,615,462 | 4,486,723 | 5,410,788 | 6,591,152 | +3,975,690 | +152% |
| T. Rowe Price Investment Mgmt | SC 13G/A | 11,447,188 | — | — | — | 5,629,965 | — | — |
| Newtyn Management, LLC | SC 13G + 13G/A | — | — | 2,700,000 | — | 4,558,472 | +1,858,472 | +68.8% |
| Vanguard Portfolio Mgmt LLC | SC 13G (new entity) | — | — | — | — | 4,088,168 | — | — |
| Vanguard Capital Mgmt LLC | SC 13G (new entity) | — | — | — | — | 3,572,563 | — | — |
| Vanguard Group (legacy) | SC 13G/A | 6,817,412 | — | — | — | 0 | — | — |
| BlackRock, Inc. | Form 13F-HR | 8,192,533 | 10,220,863 | — | — | 10,449,127 | +2,256,594 | +27.5% |
| Rubric Capital Management LP | SC 13G/A + 13F | 6,140,000 | 4,637,738 | 4,632,800 | 3,772,219 | 3,306,281 | −1,326,519 | −28.6% |
| Invesco Ltd. | SC 13G/A | 3,226,659 | — | — | 3,447,446 | 3,117,469 | — | — |
| State Street Corp | 13F | 2,274,025 | — | — | — | — | — | — |
| ArrowMark Colorado Holdings | 13F | 1,977,697 | — | — | — | — | — | — |
| D.E. Shaw & Co., L.P. | 13F | 1,728,613 | — | — | — | — | — | — |
| JP Morgan Asset Management | 13F | 1,300,475 | — | — | — | — | — | — |
| American Century Investment | Form 13F-HR | 1,115,551 | 1,915,648 | 1,588,645 | — | 2,856,132 | +1,267,487 | +79.8% |
| Dimensional Fund Advisors LP | Form 13F-HR | 1,217,126 | 2,406,243 | — | — | 3,048,768 | +642,525 | +26.7% |
| Millennium Management LLC | 13F | 1,089,828 | — | — | — | — | — | — |
| Carlyle Partners VI Cayman | Form 4 (exited) | 0 | 0 | 0 | 0 | 0 | — | — |
Only one number here is firm — Rubric's. The others are reasoned estimates from the documented build history of each holder, anchored to QDEL's quarter-end prices during those build periods. Confidence ratings reflect how much we know about timing and sequencing.
| Holder | Est. Avg Buy Price |
Confidence | Methodology |
|---|---|---|---|
| Rubric Capital Management | $49.72 | Disclosed | Independently disclosed by gurufocus tracking: 7 purchases beginning Q3 2023, totaling 6.14M shares at peak position, at an average $49.72/share. As of Q1 2025 the holding tracked a −44.4% paper loss. The most precise number in the model. |
| T. Rowe Price Investment Mgmt | $52.00 | Med-Low | Built primarily 2022–2024. 13G history: 6.5M shares at 12/31/22 (initial), 8.7M at 12/31/23, 9.4M at 9/30/24, 11.24M at 12/31/24 (peak). Quarter-end prices during build: $86 → $74 → $43 → $44. Since they've been net sellers in 2025–2026 (now 5.63M), remaining shares are the oldest, highest-cost tranche. Range $48–$58; midpoint $52. |
| FMR LLC (Fidelity) | $28.00 | Med-Low | Held only ~1.28M shares as of Q1 2025 (13F basis). Filed first 13G crossing 5% in 2026 at 6.59M, then 7.85M — meaning ~6.5M shares were added during 2025–early 2026 when QDEL traded $20–$45 (mostly $25–$35). Pre-2025 legacy sleeve of ~1.3M likely $40–$60. Blended estimate $28–$32; using $28 to reflect heavy 2025–2026 weighting. |
| Newtyn Management, LLC | $28.00 | Medium | Position initiated late 2024 / early 2025. Q3 2025 13F showed 2.7M shares at reported value $79.5M → implied avg of ~$29.4 at marks. Subsequent adds of 1.86M (Q3 2025 → Q1 2026) and 741K (Q1 2026 → 4/29/2026) at $23 to $11. Most adds in the $20–$30 range. Estimate $25–$30; using $28. |
| Vanguard (both entities) | $42.00 | Low-Med | Index complex aggregating QDEL since the 2022 merger. Cost basis approximates time-weighted price across rebalancing flows. With QDEL above $45 through most of 2022–early 2024 (high inflow as index inclusion stabilized) and below $35 since early 2025, weighted average likely $40–$45. |
| BlackRock, Inc. | $45.00 | Low-Med | Largest QDEL holder per 13F-HR filed 5/13/2026: 10,449,127 (15.34%). Largely passive (iShares Core S&P Small-Cap ETF — IJR — is a major sleeve, plus various active mandates). Q1'25 8.19M → Q2'25 10.22M → Q1'26 10.45M. ~2.26M added across 2025-2026 at $20-$25 average; pre-2025 holdings at $50+ via index inclusion post-merger. Blended estimate $40-$45. |
| Invesco Ltd. | $43.00 | Medium | Heavy build occurred Q4 2024 (+71.7% / +1.44M shares to 3.45M total) when QDEL averaged $40–$45. Q1 2025 trim of ~221K @ ~$35. Since Q1 2026 position is 3.12M (only ~330K below Q4 2024 peak), remaining shares are mostly Q4 2024 vintage. Estimate $42–$45. |
| Carlyle Partners VI (exited) | — | N/A | Original cost basis was Ortho Clinical Diagnostics buyout (2014, $4.15B + debt) then re-anchored at the May 2022 merger close. Exit price $35.31/share generated ~$291.7M for the final 8.26M tranche. Not relevant to current ownership. |
Every 5%+ beneficial ownership disclosure and amendment that touches the past three quarters, plus the Carlyle Form 4 from November 2024 that set the stage. Filings flow newest-first.
Inputs to the cost-basis estimates. Sources include Macrotrends, calculated marks from 13F valuations (T. Rowe Price's reported $-value ÷ shares yields the implied quarter-end mark), and contemporaneous news references.
| Quarter | Date | Approx. Close | Source / Reference | Context |
|---|---|---|---|---|
| Q2 2022 | 6/30/2022 | $92.00 | Macrotrends | Post-merger close (5/27/2022) |
| Q3 2022 | 9/30/2022 | $72.00 | Macrotrends | Early integration |
| Q4 2022 | 12/30/2022 | $86.00 | Macrotrends | Year-end 2022 |
| Q1 2023 | 3/31/2023 | $83.00 | Macrotrends | Pre-respiratory-season weakness |
| Q2 2023 | 6/30/2023 | $83.00 | Macrotrends | Stable |
| Q3 2023 | 9/29/2023 | $70.00 | Macrotrends | Initial softening |
| Q4 2023 | 12/29/2023 | $74.00 | Macrotrends | Year-end 2023 |
| Q1 2024 | 3/29/2024 | $48.00 | Macrotrends | Securities class actions; multiple PT cuts |
| Q2 2024 | 6/28/2024 | $34.00 | Macrotrends | Continued underperformance |
| Q3 2024 | 9/30/2024 | $43.00 | T. Rowe 13F valuation | Rubric added 4.2M @ $45.60 |
| Q4 2024 | 12/31/2024 | $44.55 | Calc: $500.69M / 11.24M sh | Carlyle exited 11/21/24 @ $35.31 |
| Q1 2025 | 3/31/2025 | $34.97 | Calc: $400.31M / 11.45M sh | Mar 10, 2025 reference: $38.68 |
| Q2 2025 | 6/30/2025 | $27.00 | Macrotrends + news | UBS PT $26; JPMorgan PT $25 |
| Q3 2025 | 9/30/2025 | $29.00 | Macrotrends | Modest rebound on Q2'25 beat |
| Q4 2025 | 12/31/2025 | $28.48 | INDmoney 12/24/2025 | Year-end 2025 |
| Q1 2026 | 3/31/2026 | $23.00 | Yahoo Finance recent | Pre-earnings; revenue warning 4/15/26 |
| Current | 5/18/2026 | $11.50 | CNN $11.39 / WallStreetZen $10.32 | Post Q1'26 earnings miss (5/5/2026); guidance cut |
Every number in this report traces to one of the documents below. Schedule 13G/13G-A filings filed in the April–May 2026 window are the spine; the proxy gave us the record-date share count; the 13F summaries and aggregator data filled in the quarterly cadence between filings.
Major Holders Research publishes analyses of institutional ownership shifts at single-name US-listed equities, sourcing exclusively from SEC filings and disclosed positions. Cost basis estimates carry uncertainty and are clearly labeled. This document is for informational purposes only and does not constitute investment advice.