Armstrong World Industries, Inc.
US ˙ NYSE ˙ US04247X1028

SecurityAWI / Armstrong World Industries, Inc.
InstitutionFirst Manhattan Co
Latest Disclosed Ownership4,700 shares
Latest Disclosed Value $ 774,560
First Manhattan Co reports 18.12% decrease in ownership of AWI / Armstrong World Industries, Inc.

On May 15, 2026 - First Manhattan Co filed a 13F-HR form disclosing ownership of 4,700 shares of Armstrong World Industries, Inc. (US:AWI) valued at $774,560 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 17, 2026 disclosing 5,740 shares of Armstrong World Industries, Inc.. This represents a change in shares of -18.12% during the quarter. The current value of the position is $720,087 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)
2026-05-15 2026-03-31 13F ARMSTRONG WORLD INDS INC COM 04247X102 4,700 -1,040 -18.12 775 -29.38 0.0021
2026-02-17 2025-12-31 13F ARMSTRONG WORLD INDS INC COM 04247X102 5,740 -200 -3.37 1,097 -5.84 0.0029
2025-11-14 2025-09-30 13F ARMSTRONG WORLD INDS INC COM 04247X102 5,940 -1,625 -21.48 1,164 -5.21 0.0031
2025-08-14 2025-06-30 13F ARMSTRONG WORLD INDS INC COM 04247X102 7,565 -60 -0.79 1,229 14.34 0.0035
2025-05-15 2025-03-31 13F ARMSTRONG WORLD INDS INC COM 04247X102 7,625 -125 -1.61 1,074 -1.92 0.0031
2025-02-14 2024-12-31 13F ARMSTRONG WORLD INDS INC COM 04247X102 7,750 -190 -2.39 1,095 4.99 0.0032
2024-11-14 2024-09-30 13F ARMSTRONG WORLD INDS INC COM 04247X102 7,940 -260 -3.17 1,044 12.39 0.0031
2024-08-15 2024-06-30 13F/A-1 ARMSTRONG WORLD INDS INC COM 04247X102 8,200 -400 -4.65 929 -13.11 0.0030
2024-08-14 2024-06-30 13F ARMSTRONG WORLD INDS INC COM 04247X102 8,200 -400 929 0.0030
2024-05-15 2024-03-31 13F ARMSTRONG WORLD INDS INC COM 04247X102 8,600 -1,100 -11.34 1,068 12.07 0.0035
2024-02-13 2023-12-31 13F ARMSTRONG WORLD INDS INC COM 04247X102 9,700 -300 -3.00 954 32.36 0.0033
2023-11-14 2023-09-30 13F ARMSTRONG WORLD INDS INC COM 04247X102 10,000 -900 -8.26 720 -10.00 0.0027
2023-08-14 2023-06-30 13F ARMSTRONG WORLD INDS INC COM 04247X102 10,900 -3,500 -24.31 801 -21.95 0.0029
2023-05-15 2023-03-31 13F ARMSTRONG WORLD INDS INC COM 04247X102 14,400 -250 -1.71 1,026 2.09 0.0039
2023-02-14 2022-12-31 13F ARMSTRONG WORLD INDS INC COM 04247X102 14,650 0 0.00 1,005 -13.45 0.0037
2022-11-14 2022-09-30 13F ARMSTRONG WORLD INDS INC COM 04247X102 14,650 -850 -5.48 1,160 -0.09 0.0049
2022-08-15 2022-06-30 13F ARMSTRONG WORLD INDS INC COM 04247X102 15,500 -100 -0.64 1,161 -17.31 0.0047
2022-05-16 2022-03-31 13F ARMSTRONG WORLD INDS INC COM 04247X102 15,600 15,600 1,404 0.0046
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.