American Tower Corporation
MX ˙ BMV ˙ US03027X1000
SecurityMX:AMT / American Tower Corporation
InstitutionKnuff & Co LLC
Latest Disclosed Ownership2,975 shares
Latest Disclosed Value $ 513,426
Knuff & Co LLC reports 83.30% decrease in ownership of AMT / American Tower Corporation

On May 11, 2026 - Knuff & Co LLC filed a 13F-HR form disclosing ownership of 2,975 shares of American Tower Corporation (MX:AMT) valued at $513,426 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 4, 2026 disclosing 17,810 shares of American Tower Corporation. This represents a change in shares of -83.30% during the quarter.

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)
2026-05-11 2026-03-31 13F AMERICAN TOWER COM 03027X100 2,975 -14,835 -83.30 513 -83.59 0.1547
2026-02-04 2025-12-31 13F AMERICAN TOWER COM 03027X100 17,810 -6,935 -28.03 3,127 -34.30 0.9216
2025-11-13 2025-09-30 13F AMERICAN TOWER COM 03027X100 24,745 -144 -0.58 4,759 -13.49 1.3787
2025-08-13 2025-06-30 13F AMERICAN TOWER COM 03027X100 24,889 676 2.79 5,501 4.40 1.7321
2025-05-13 2025-03-31 13F AMERICAN TOWER COM 03027X100 24,213 1,390 6.09 5,269 25.88 1.7679
2025-02-10 2024-12-31 13F AMERICAN TOWER COM 03027X100 22,823 845 3.84 4,186 -18.12 1.2723
2024-11-07 2024-09-30 13F AMERICAN TOWER COM 03027X100 21,978 416 1.93 5,111 21.95 1.5599
2024-08-01 2024-06-30 13F AMERICAN TOWER COM 03027X100 21,562 17 0.08 4,191 -1.55 1.3603
2024-05-09 2024-03-31 13F AMERICAN TOWER COM 03027X100 21,545 -957 -4.25 4,257 -12.35 1.4310
2024-02-06 2023-12-31 13F AMERICAN TOWER COM 03027X100 22,502 123 0.55 4,858 31.98 1.7706
2023-11-09 2023-09-30 13F AMERICAN TOWER COM 03027X100 22,379 -1,926 -7.92 3,680 -21.92 1.4671
2023-08-08 2023-06-30 13F AMERICAN TOWER COM 03027X100 24,305 -356 -1.44 4,714 -6.47 1.7662
2023-05-09 2023-03-31 13F AMERICAN TOWER COM 03027X100 24,661 -1,204 -4.65 5,039 -8.03 1.9948
2023-02-09 2022-12-31 13F AMERICAN TOWER COM 03027X100 25,865 121 0.47 5,480 -0.87 2.3364
2022-11-04 2022-09-30 13F AMERICAN TOWER COM 03027X100 25,744 452 1.79 5,527 -14.50 2.6157
2022-08-08 2022-06-30 13F AMERICAN TOWER COM 03027X100 25,292 -403 -1.57 6,464 0.14 2.9066
2022-05-10 2022-03-31 13F AMERICAN TOWER COM 03027X100 25,695 -400 -1.53 6,455 -15.43 2.3412
2022-02-09 2021-12-31 13F AMERICAN TOWER COM 03027X100 26,095 -1,077 -3.96 7,633 5.84 2.3658
2021-11-16 2021-09-30 13F AMERICAN TOWER COM 03027X100 27,172 -28 -0.10 7,212 -1.85 2.6977
2021-08-10 2021-06-30 13F AMERICAN TOWER COM 03027X100 27,200 -873 -3.11 7,348 9.49 2.7300
2021-05-04 2021-03-31 13F AMERICAN TOWER COM 03027X100 28,073 711 2.60 6,711 9.26 2.8712
2021-02-03 2020-12-31 13F AMERICAN TOWER COM 03027X100 27,362 1,021 3.88 6,142 -3.53 2.5308
2020-11-03 2020-09-30 13F AMERICAN TOWER COM 03027X100 26,341 3,502 15.33 6,367 7.82 2.9975
2020-08-07 2020-06-30 13F AMERICAN TOWER COM 03027X100 22,839 1,514 7.10 5,905 27.15 3.2348
2020-05-13 2020-03-31 13F AMERICAN TOWER COM 03027X100 21,325 335 1.60 4,644 -3.73 3.3719
2020-02-11 2019-12-31 13F AMERICAN TOWER CORP NEW COM REIT 03027X100 20,990 2,130 11.29 4,824 15.66 2.8849
2019-11-05 2019-09-30 13F AMERICAN TOWER CORP NEW COM REIT 03027X100 18,860 470 2.56 4,171 10.93 2.8668
2019-08-08 2019-06-30 13F AMERICAN TOWER CORP NEW COM REIT 03027X100 18,390 50 0.27 3,760 4.04 2.6757
2019-05-08 2019-03-31 13F AMERICAN TOWER CORP NEW COM REIT 03027X100 18,340 1,805 10.92 3,614 38.15 2.7753
2019-02-14 2018-12-31 13F AMERICAN TOWER CORP NEW COM REIT 03027X100 16,535 16,535 2,616 2.5699
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.