American Tower Corporation
MX ˙ BMV ˙ US03027X1000
SecurityMX:AMT / American Tower Corporation
InstitutionCornerstone Advisory, LLC
Latest Disclosed Ownership3,172 shares
Latest Disclosed Value $ 547,346
Cornerstone Advisory, LLC reports 9.64% increase in ownership of AMT / American Tower Corporation

On May 4, 2026 - Cornerstone Advisory, LLC filed a 13F-HR form disclosing ownership of 3,172 shares of American Tower Corporation (MX:AMT) valued at $547,346 USD as of March 31, 2026. The entity filed a previous 13F-HR on January 28, 2026 disclosing 2,893 shares of American Tower Corporation. This represents a change in shares of 9.64% 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)
2026-05-04 2026-03-31 13F AMERICAN TOWER COM 03027X100 3,172 279 9.64 547 7.89 0.0518
2026-01-28 2025-12-31 13F AMERICAN TOWER CORP COM 03027X100 2,893 -341 -10.54 508 -18.36 0.0484
2025-11-07 2025-09-30 13F AMERICAN TOWER CORP COM 03027X100 3,234 17 0.53 622 -12.66 0.0611
2025-07-30 2025-06-30 13F AMERICAN TOWER CORP COM 03027X100 3,217 -3 -0.09 711 -1.25 0.0764
2025-05-07 2025-03-31 13F AMERICAN TOWER CORP COM 03027X100 3,220 96 3.07 721 21.83 0.0841
2025-02-18 2024-12-31 13F AMERICAN TOWER CORP COM 03027X100 3,124 113 3.75 592 -15.57 0.0672
2024-11-12 2024-09-30 13F AMERICAN TOWER CORP COM 03027X100 3,011 23 0.77 700 20.69 0.0921
2024-08-14 2024-06-30 13F AMERICAN TOWER CORP COM 03027X100 2,988 -928 -23.70 581 -24.97 0.0817
2024-05-08 2024-03-31 13F AMERICAN TOWER CORP COM 03027X100 3,916 -33 -0.84 774 -9.27 0.1103
2024-02-13 2023-12-31 13F AMERICAN TOWER CORP COM 03027X100 3,949 276 7.51 853 41.06 0.1329
2023-11-14 2023-09-30 13F AMERICAN TOWER CORP COM 03027X100 3,673 -124 -3.27 604 -17.93 0.1057
2023-07-20 2023-06-30 13F AMERICAN TOWER CORP COM 03027X100 3,797 -1,700 -30.93 736 -34.46 0.1294
2023-05-04 2023-03-31 13F AMERICAN TOWER CORP COM 03027X100 5,497 409 8.04 1,123 4.27 0.2023
2023-02-13 2022-12-31 13F AMERICAN TOWER CORP COM 03027X100 5,088 333 7.00 1,078 5.48 0.2124
2022-10-26 2022-09-30 13F AMERICAN TOWER CORP COM 03027X100 4,755 -350 -6.86 1,021 -21.76 0.2280
2022-08-02 2022-06-30 13F AMERICAN TOWER CORP COM 03027X100 5,105 -1,368 -21.13 1,305 -19.79 0.2985
2022-05-20 2022-03-31 13F AMERICAN TOWER CORP COM 03027X100 6,473 -48 -0.74 1,627 -14.68 0.2481
2022-02-23 2021-12-31 13F AMERICAN TOWER CORP COM 03027X100 6,521 -1,948 -23.00 1,907 -15.17 0.2741
2021-11-16 2021-09-30 13F AMERICAN TOWER CORP COM 03027X100 8,469 0 0.00 2,248 -1.75 0.3722
2021-08-16 2021-06-30 13F AMERICAN TOWER CORP COM 03027X100 8,469 -750 -8.14 2,288 3.81 0.3854
2021-05-13 2021-03-31 13F AMERICAN TOWER CORP COM 03027X100 9,219 5,218 130.42 2,204 145.43 0.4171
2021-05-11 2020-12-31 13F AMERICAN TOWER CORP COM 03027X100 4,001 525 15.10 898 6.90 0.1818
2020-11-12 2020-09-30 13F AMERICAN TOWER CORP COM 03027X100 3,476 0 0.00 840 -6.56 0.1960
2020-08-10 2020-06-30 13F AMERICAN TOWER CORP COM 03027X100 3,476 0 0.00 899 18.76 0.2345
2020-05-11 2020-03-31 13F AMERICAN TOWER CORP COM 03027X100 3,476 0 0.00 757 -5.26 0.2302
2020-02-12 2019-12-31 13F AMERICAN TOWER CORP COM 03027X100 3,476 0 0.00 799 3.90 0.1654
2019-11-12 2019-09-30 13F AMERICAN TOWER CORP COM 03027X100 3,476 18 0.52 769 8.77 0.1659
2019-08-08 2019-06-30 13F AMERICAN TOWER CORP COM 03027X100 3,458 0 0.00 707 3.82 0.1533
2019-05-08 2019-03-31 13F AMERICAN TOWER CORP COM 03027X100 3,458 0 0.00 681 24.50 0.1498
2019-02-12 2018-12-31 13F AMERICAN TOWER CORP COM 03027X100 3,458 -95 -2.67 547 6.01 0.1435
2018-11-13 2018-09-30 13F AMERICAN TOWER CORP COM 03027X100 3,553 0 0.00 516 0.78 0.1530
2018-08-09 2018-06-30 13F AMERICAN TOWER CORP COM 03027X100 3,553 0 0.00 512 -0.78 0.1685
2018-05-10 2018-03-31 13F AMERICAN TOWER CORP COM 03027X100 3,553 0 0.00 516 1.78 0.1858
2018-02-09 2017-12-31 13F AMERICAN TOWER CORP COM 03027X100 3,553 0 0.00 507 4.32 0.1737
2017-11-14 2017-09-30 13F AMERICAN TOWER CORP COM 03027X100 3,553 0 0.00 486 3.40 0.1645
2017-08-08 2017-06-30 13F AMERICAN TOWER CORP COM 03027X100 3,553 -34 -0.95 470 7.80 0.1573
2017-05-15 2017-03-31 13F AMERICAN TOWER CORP COM 03027X100 3,587 34 0.96 436 16.27 0.2201
2017-02-13 2016-12-31 13F AMERICAN TOWER CORP COM 03027X100 3,553 0 0.00 375 -6.95 0.2814
2016-11-10 2016-09-30 13F AMERICAN TOWER CORP COM 03027X100 3,553 0 0.00 403 -0.25 0.3309
2016-08-10 2016-06-30 13F AMERICAN TOWER CORP COM 03027X100 3,553 0 0.00 404 10.99 0.3396
2016-05-16 2016-03-31 13F AMERICAN TOWER CORP COM 03027X100 3,553 -200 -5.33 364 0.00 0.3110
2016-03-03 2015-12-31 13F AMERICAN TOWER CORP COM 03027X100 3,753 3,753 364 0.3134
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.