Allison Transmission Holdings, Inc.
US ˙ NYSE ˙ US01973R1014

SecurityALSN / Allison Transmission Holdings, Inc.
InstitutionJanus Henderson Group Plc
Latest Disclosed Ownership491,105 shares
Latest Disclosed Value $ 57,530,310
Janus Henderson Group Plc reports 32.74% increase in ownership of ALSN / Allison Transmission Holdings, Inc.

On May 18, 2026 - Janus Henderson Group Plc filed a 13F-HR/A form disclosing ownership of 491,105 shares of Allison Transmission Holdings, Inc. (US:ALSN) valued at $57,488,751 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 17, 2026 disclosing 369,976 shares of Allison Transmission Holdings, Inc.. This represents a change in shares of 32.74% during the quarter. The current value of the position is $58,137,010 USD.

Institutional Ownership: 13F and NPORT Filings

The Security and Class in the table below are shown exactly as filed by the investor. We do our best to track continuity of investments through acquisitions, and this will be reflected in the table as changes in names. In addition to descriptive data, performance of the investment is shown over time. To calculate quarterly performance, we first calculate cost basis of the shares purchased during the quarter, then use that to calculate gross profit. Quarterly return is Gross Profit / Starting Portfolio value.

Note that cost basis is calculated and stored in thousands, so small quarterly changes in shares frequently result in a cost basis of zero.

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Disclosed Equity Positions (from 13F/NPORT Filings)
File
Date		 Effective
Date		Form Security Class ID Avg Price
Paid (Est)		 Reported
Shares		 ΔShares ΔShares
(%)		 Reported
Value
(x1000)		 ΔValue
(%)		 Alloc
(%)		 ΔAlloc ΔAlloc (%) Cost Basis
(x1000)		 Unrealized
Gain/Loss
(x1000)
2026-05-18 2026-03-31 13F/A-1 ALLISON TRANSMISSION HLDGS I COM 01973R101 491,105 121,129 32.74 57,530 58.77 0.0097
2026-05-15 2026-03-31 13F ALLISON TRANSMISSION HLDGS I COM 01973R101 491,105 121,129 57,530 0.0107
2026-02-17 2025-12-31 13F ALLISON TRANSMISSION HLDGS I COM 01973R101 369,976 113,108 44.03 36,234 66.28 0.0162
2025-11-14 2025-09-30 13F ALLISON TRANSMISSION HLDGS I COM 01973R101 256,868 37,460 17.07 21,792 4.51 0.0099
2025-08-14 2025-06-30 13F ALLISON TRANSMISSION HLDGS I COM 01973R101 219,408 32,672 17.50 20,850 16.19 0.0102
2025-05-15 2025-03-31 13F ALLISON TRANSMISSION HLDGS I COM 01973R101 186,736 378 0.20 17,944 -10.93 0.0098
2025-02-14 2024-12-31 13F ALLISON TRANSMISSION HLDGS I COM 01973R101 186,358 112,710 153.04 20,145 184.73 0.0102
2024-11-14 2024-09-30 13F ALLISON TRANSMISSION HLDGS I COM 01973R101 73,648 11,931 19.33 7,075 51.01 0.0036
2024-08-14 2024-06-30 13F ALLISON TRANSMISSION HLDGS I COM 01973R101 61,717 4,719 8.28 4,685 1.28 0.0025
2024-05-15 2024-03-31 13F ALLISON TRANSMISSION HLDGS I COM 01973R101 56,998 11,495 25.26 4,627 74.90 0.0025
2024-02-14 2023-12-31 13F ALLISON TRANSMISSION HLDGS I COM 01973R101 45,503 -68 -0.15 2,646 -1.71 0.0016
2023-11-14 2023-09-30 13F ALLISON TRANSMISSION HLDGS I COM 01973R101 45,571 269 0.59 2,692 5.24 0.0018
2023-08-14 2023-06-30 13F ALLISON TRANSMISSION HLDGS I COM 01973R101 45,302 1,303 2.96 2,557 28.49 0.0016
2023-05-15 2023-03-31 13F ALLISON TRANSMISSION HLDGS I COM 01973R101 43,999 25,327 135.64 1,990 156.11 0.0013
2023-02-14 2022-12-31 13F ALLISON TRANSMISSION HLDGS I COM 01973R101 18,672 1,500 8.74 777 33.97 0.0006
2023-01-13 2022-09-30 13F/A-1 ALLISON TRANSMISSION HLDGS I COM 01973R101 17,172 -2,160 -11.17 580 -21.94 0.0004
2022-11-14 2022-09-30 13F ALLISON TRANSMISSION HLDGS I COM 01973R101 17,172 -2,160 580 0.0004
2022-08-15 2022-06-30 13F ALLISON TRANSMISSION HLDGS I COM 01973R101 19,332 -79 -0.41 743 -2.49 0.0005
2022-05-16 2022-03-31 13F ALLISON TRANSMISSION HLDGS I COM 01973R101 19,411 2,186 12.69 762 21.53 0.0004
2022-02-14 2021-12-31 13F ALLISON TRANSMISSION HLDGS I COM 01973R101 17,225 -61,373 -78.08 627 -77.41 0.0003
2021-11-16 2021-09-30 13F ALLISON TRANSMISSION HLDGS I COM 01973R101 78,598 78,598 2,776 0.0012
2021-05-17 2021-03-31 13F ALLISON TRANSMISSION HLDGS I COM 01973R101 0 -13,850 -100.00 0 -100.00
2021-02-16 2020-12-31 13F ALLISON TRANSMISSION HLDGS I COM 01973R101 13,850 1,149 9.05 597 33.86 0.0003
2020-11-16 2020-09-30 13F ALLISON TRANSMISSION HLDGS I COM 01973R101 12,701 -5,094 -28.63 446 -31.91 0.0002
2020-08-14 2020-06-30 13F ALLISON TRANSMISSION HLDGS I COM 01973R101 17,795 -15,330 -46.28 655 -39.35 0.0004
2020-05-14 2020-03-31 13F ALLISON TRANSMISSION HLDGS I COM 01973R101 33,125 6,456 24.21 1,080 -16.21 0.0007
2020-02-18 2019-12-31 13F ALLISON TRANSMISSION HLDGS I COM 01973R101 26,669 -13,134 -33.00 1,289 -31.18 0.0007
2019-11-14 2019-09-30 13F ALLISON TRANSMISSION HLDGS I COM 01973R101 39,803 -109,735 -73.38 1,873 -72.98 0.0010
2019-07-31 2019-06-30 13F ALLISON TRANSMISSION HLDGS I COM 01973R101 149,538 8,116 5.74 6,931 9.10 0.0038
2019-04-30 2019-03-31 13F ALLISON TRANSMISSION HLDGS I COM 01973R101 141,422 70,722 100.03 6,353 104.67 0.0035
2019-02-06 2018-12-31 13F ALLISON TRANSMISSION HLDGS I COM 01973R101 70,700 56,200 387.59 3,104 311.67 0.0020
2018-11-09 2018-09-30 13F ALLISON TRANSMISSION HLDGS I COM 01973R101 14,500 -1,500 -9.38 754 16.36 0.0004
2018-08-10 2018-06-30 13F ALLISON TRANSMISSION HLDGS I COM 01973R101 16,000 -20,500 -56.16 648 -54.56 0.0004
2018-05-14 2018-03-31 13F ALLISON TRANSMISSION HLDGS I COM 01973R101 36,500 36,500 1,426 0.0008
2017-11-14 2017-09-30 13F ALLISON TRANSMISSION HLDGS I COM 01973R101 0 -10,000 -100.00 0 -100.00
2017-08-17 2017-06-30 13F/A-1 ALLISON TRANSMISSION HLDGS I COM 01973R101 10,000 -215,000 -95.56 375 -93.96 0.0003
2017-08-14 2017-06-30 13F ALLISON TRANSMISSION HLDGS I COM 01973R101 10,000 375
2014-01-14 2013-12-31 13F ALLISON TRANSMISSION HLDGS I COM 01973R101 225,000 225,000 6,212 0.0628
Legend
Shares
The total number of shares held by the institution at the end of the reporting period (the effective date). This is provided in the filing.
Value
The total value of the shares as of the effective date. This is provided in the filing.
Avg. Share Price
The weighted average share price of the shares held by the institution. We use FIFO accounting to determine this price
Class
This is the security class as indicated by the filer. There are a variety of values for this field. Common values include "EC" = equity common, "EP" - equity preferred
Allocation (%)
The percent of the institution's portfolio that this position represents. This is provided in NPORT filings. For 13F filings, we calculate it.
Change in Allocation
The change in allocation from the prior reporting period. This is calculated as current allocation - prior allocation.
Change in Allocation (%)
The percent change in allocation from the prior reporting period. This is calculated as (current allocation - prior allocation) / prior allocation.
Cost Basis
The total cost of the shares held. This is calculated as reported shares * avg. share price
Unrealized Gain/Loss
This is the market value of the position as of the effective date minus the cost basis.