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.