American Tower Corporation
US ˙ NYSE ˙ US03027X1000

SecurityAMT / American Tower Corporation
InstitutionChicago Capital, LLC
Latest Disclosed Ownership4,930 shares
Latest Disclosed Value $ 850,783
Chicago Capital, LLC reports 1.71% increase in ownership of AMT / American Tower Corporation

On April 23, 2026 - Chicago Capital, LLC filed a 13F-HR form disclosing ownership of 4,930 shares of American Tower Corporation (US:AMT) valued at $850,819 USD as of March 31, 2026. The entity filed a previous 13F-HR on January 26, 2026 disclosing 4,847 shares of American Tower Corporation. This represents a change in shares of 1.71% during the quarter. The current value of the position is $898,443 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.

Upgrade to unlock premium data and export to Excel .

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)
2026-04-23 2026-03-31 13F AMERICAN TOWER COM 03027X100 4,930 83 1.71 851 0.00 0.0229
2026-01-26 2025-12-31 13F AMERICAN TOWER CORP COM 03027X100 4,847 -116 -2.34 851 -10.90 0.0210
2025-10-22 2025-09-30 13F AMERICAN TOWER CORP COM 03027X100 4,963 -30 -0.60 954 -13.51 0.0235
2025-07-17 2025-06-30 13F AMERICAN TOWER CORP COM 03027X100 4,993 30 0.60 1,104 2.22 0.0272
2025-04-17 2025-03-31 13F AMERICAN TOWER CORP COM 03027X100 4,963 1,549 45.37 1,080 72.36 0.0305
2025-01-24 2024-12-31 13F AMERICAN TOWER CORP COM 03027X100 3,414 0 0.00 626 -21.06 0.0166
2024-10-18 2024-09-30 13F AMERICAN TOWER CORP COM 03027X100 3,414 -25 -0.73 794 18.71 0.0220
2024-08-06 2024-06-30 13F AMERICAN TOWER CORP COM 03027X100 3,439 -334 -8.85 668 -10.34 0.0199
2024-04-15 2024-03-31 13F AMERICAN TOWER CORP COM 03027X100 3,773 0 0.00 745 -8.48 0.0227
2024-01-22 2023-12-31 13F AMERICAN TOWER CORP COM 03027X100 3,773 635 20.24 814 57.75 0.0293
2023-10-25 2023-09-30 13F AMERICAN TOWER CORP COM 03027X100 3,138 5 0.16 516 -14.99 0.0241
2023-07-20 2023-06-30 13F AMERICAN TOWER CORP COM 03027X100 3,133 70 2.29 608 -2.88 0.0274
2023-04-18 2023-03-31 13F AMERICAN TOWER CORP COM 03027X100 3,063 55 1.83 626 -1.88 0.0311
2023-01-20 2022-12-31 13F AMERICAN TOWER CORP COM 03027X100 3,008 -14 -0.46 637 -1.85 0.0353
2022-10-14 2022-09-30 13F AMERICAN TOWER CORP COM 03027X100 3,022 0 0.00 649 -15.93 0.0375
2022-07-21 2022-06-30 13F AMERICAN TOWER CORP COM 03027X100 3,022 0 0.00 772 1.71 0.0426
2022-04-21 2022-03-31 13F AMERICAN TOWER CORP COM 03027X100 3,022 -132 -4.19 759 -17.77 0.0327
2022-01-20 2021-12-31 13F AMERICAN TOWER CORP COM 03027X100 3,154 -40 -1.25 923 8.84 0.0344
2021-10-28 2021-09-30 13F AMERICAN TOWER CORP COM 03027X100 3,194 14 0.44 848 -1.28 0.0322
2021-07-22 2021-06-30 13F AMERICAN TOWER CORP COM 03027X100 3,180 0 0.00 859 13.03 0.0336
2021-04-13 2021-03-31 13F AMERICAN TOWER CORP COM 03027X100 3,180 100 3.25 760 9.99 0.0321
2021-01-25 2020-12-31 13F AMERICAN TOWER CORP COM 03027X100 3,080 -4,944 -61.62 691 -64.38 0.0309
2020-10-13 2020-09-30 13F AMERICAN TOWER CORP COM 03027X100 8,024 299 3.87 1,940 -2.85 0.0997
2020-07-29 2020-06-30 13F AMERICAN TOWER CORP COM 03027X100 7,725 0 0.00 1,997 18.73 0.1157
2020-04-21 2020-03-31 13F AMERICAN TOWER CORP COM 03027X100 7,725 0 0.00 1,682 -5.24 0.1356
2020-01-14 2019-12-31 13F AMERICAN TOWER CORP COM 03027X100 7,725 0 0.00 1,775 3.92 0.1083
2019-10-28 2019-09-30 13F AMERICAN TOWER CLASS A 03027X100 7,725 0 0.00 1,708 8.17 0.1144
2019-07-11 2019-06-30 13F AMERICAN TOWER CLASS A 03027X100 7,725 -579 -6.97 1,579 -3.48 0.1010
2019-04-23 2019-03-31 13F AMERICAN TOWER CLASS A 03027X100 8,304 1,948 30.65 1,636 62.79 0.1112
2019-02-11 2018-12-31 13F AMERICAN TOWER COM CL A 03027X100 6,356 1,231 24.02 1,005 34.90 0.0820
2018-11-02 2018-09-30 13F AMERICAN TOWER COM CL A 03027X100 5,125 435 9.28 745 10.21 0.0515
2018-07-19 2018-06-30 13F AMERICAN TOWER COM CL A 03027X100 4,690 4,690 676 0.0545
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.