American Tower Corporation
US ˙ NYSE ˙ US03027X1000

SecurityAMT / American Tower Corporation
InstitutionCitigroup Inc
Latest Disclosed Ownership633,831 shares
Latest Disclosed Value $ 109,386,612
Citigroup Inc ownership in AMT / American Tower Corporation

On May 11, 2026 - Citigroup Inc filed a 13F-HR form disclosing ownership of 633,831 shares of American Tower Corporation (US:AMT) valued at $109,386,554 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 13, 2026 disclosing 615,309 shares of American Tower Corporation. This represents a change in shares of 3.01% during the quarter. The current value of the position is $115,509,361 USD.

Citigroup Inc has a history of taking positions in derivatives of the underlying security (AMT) in the form of stock options. The firm currently holds call options representing 28,000 of underlying shares valued at $4,832,240 USD and put options representing 42,000 of underlying shares valued at $7,248,360 USD .

Note: prior versions of this page mistakenly stated that the share values represented the number of options, not the number of underlying shares. For more information on the data backing these reports, please see the SEC document Frequently Asked Questions About Form 13F.

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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Institutional Put/Call Ratios
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In addition to reporting standard equity and debt issues, institutions with more than 100MM assets under management must also disclose their put and call option holdings. Since put options generally indicate negative sentiment, and call options indicate positive sentiment, we can get a sense of the overall institutional sentiment by plotting the ratio of puts to calls. The chart to the right plots the historical put/call ratio for this instrument.

Using Put/Call Ratio as an indicator of investor sentiment overcomes one of the key deficiencies of using total institutional ownership, which is that a significant amount of assets under management are invested passively to track indices. Passively-managed funds do not typically buy options, so the put/call ratio indicator more closely tracks the sentiment of actively-managed funds.

AMT / American Tower Corporation Historical Put/Call Ratio
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 633,831 18,522 3.01 109,387 1.26 0.0466
2026-02-13 2025-12-31 13F AMERICAN TOWER CORP COM 03027X100 615,309 -138,398 -18.36 108,030 -25.47 0.0477
2025-11-10 2025-09-30 13F AMERICAN TOWER CORP COM 03027X100 753,707 212,916 39.37 144,953 21.27 0.0646
2025-08-11 2025-06-30 13F AMERICAN TOWER CORP COM 03027X100 540,791 -67,697 -11.13 119,526 -9.73 0.0587
2025-05-12 2025-03-31 13F AMERICAN TOWER CORP COM 03027X100 608,488 91,254 17.64 132,407 39.57 0.0677
2025-02-12 2024-12-31 13F AMERICAN TOWER CORP COM 03027X100 517,234 -103,744 -16.71 94,866 -34.31 0.0563
2024-11-12 2024-09-30 13F AMERICAN TOWER CORP COM 03027X100 620,978 -390,601 -38.61 144,415 -26.56 0.0836
2024-08-12 2024-06-30 13F AMERICAN TOWER CORP COM 03027X100 1,011,579 234,017 30.10 196,631 27.98 0.1260
2024-05-10 2024-03-31 13F AMERICAN TOWER CORP COM 03027X100 777,562 208,864 36.73 153,638 25.14 0.1009
2024-02-09 2023-12-31 13F AMERICAN TOWER CORP COM 03027X100 568,698 41,137 7.80 122,771 41.51 0.0865
2023-12-06 2023-09-30 13F/A-1 AMERICAN TOWER CORP COM 03027X100 527,561 60,247 12.89 86,757 -4.27 0.0649
2023-11-09 2023-09-30 13F AMERICAN TOWER CORP COM 03027X100 527,561 60,247 86,757 0.0648
2023-08-10 2023-06-30 13F AMERICAN TOWER CORP COM 03027X100 467,314 -203,458 -30.33 90,631 -33.88 0.0594
2023-05-11 2023-03-31 13F AMERICAN TOWER CORP COM 03027X100 670,772 126,512 23.24 137,066 18.87 0.0961
2023-02-09 2022-12-31 13F AMERICAN TOWER CORP COM 03027X100 544,260 -66,837 -10.94 115,307 -12.12 0.0918
2022-11-10 2022-09-30 13F AMERICAN TOWER CORP COM 03027X100 611,097 63,193 11.53 131,202 -6.31 0.0939
2022-08-10 2022-06-30 13F AMERICAN TOWER CORP COM 03027X100 547,904 -191,808 -25.93 140,038 -24.64 0.1042
2022-05-12 2022-03-31 13F AMERICAN TOWER CORP COM 03027X100 739,712 -327,973 -30.72 185,831 -40.50 0.1130
2022-02-10 2021-12-31 13F AMERICAN TOWER CORP COM 03027X100 1,067,685 32,063 3.10 312,296 13.62 0.1673
2021-11-10 2021-09-30 13F AMERICAN TOWER CORP COM 03027X100 1,035,622 -51,365 -4.73 274,865 -6.39 0.1623
2021-08-10 2021-06-30 13F AMERICAN TOWER CORP COM 03027X100 1,086,987 108,838 11.13 293,638 25.57 0.1767
2021-05-13 2021-03-31 13F AMERICAN TOWER CORP COM 03027X100 978,149 196,637 25.16 233,836 33.30 0.1513
2021-02-11 2020-12-31 13F AMERICAN TOWER CORP COM 03027X100 781,512 83,225 11.92 175,419 3.92 0.1036
2020-11-12 2020-09-30 13F AMERICAN TOWER CORP COM 03027X100 698,287 81,206 13.16 168,797 5.80 0.1101
2020-08-12 2020-06-30 13F AMERICAN TOWER CORP COM 03027X100 617,081 253,575 69.76 159,540 101.56 0.1245
2020-05-12 2020-03-31 13F AMERICAN TOWER CORP COM 03027X100 363,506 50,868 16.27 79,154 10.16 0.0716
2020-02-12 2019-12-31 13F AMERICAN TOWER CORP COM 03027X100 312,638 -175,462 -35.95 71,851 -33.43 0.0520
2019-11-08 2019-09-30 13F AMERICAN TOWER CORP COM 03027X100 488,100 -47,044 -8.79 107,933 -1.35 0.0856
2019-08-12 2019-06-30 13F AMERICAN TOWER CORP COM 03027X100 535,144 -130,355 -19.59 109,411 -16.57 0.0884
2019-05-13 2019-03-31 13F AMERICAN TOWER CORP COM 03027X100 665,499 237,159 55.37 131,143 93.54 0.1264
2019-02-12 2018-12-31 13F AMERICAN TOWER CORP COM 03027X100 428,340 -14,968 -3.38 67,759 5.19 0.0686
2018-11-13 2018-09-30 13F AMERICAN TOWER CORP COM 03027X100 443,308 55,723 14.38 64,413 15.27 0.0575
2018-08-10 2018-06-30 13F AMERICAN TOWER CORP COM 03027X100 387,585 -33,197 -7.89 55,879 -8.63 0.0514
2018-05-11 2018-03-31 13F AMERICAN TOWER CORP COM 03027X100 420,782 -24,579 -5.52 61,157 -3.75 0.0504
2018-02-12 2017-12-31 13F AMERICAN TOWER CORP COM 03027X100 445,361 -134,209 -23.16 63,540 -19.79 0.0509
2017-11-13 2017-09-30 13F AMERICAN TOWER CORP COM 03027X100 579,570 19,546 3.49 79,216 6.90 0.0648
2017-08-11 2017-06-30 13F AMERICAN TOWER CORP COM 03027X100 560,024 -28,678 -4.87 74,102 3.56 0.0668
2017-05-12 2017-03-31 13F AMERICAN TOWER CORP COM 03027X100 588,702 -12,769 -2.12 71,552 12.57 0.0638
2017-02-10 2016-12-31 13F AMERICAN TOWER CORP COM 03027X100 601,471 104,988 21.15 63,564 12.97 0.0573
2016-11-10 2016-09-30 13F AMERICAN TOWER CORP COM 03027X100 496,483 366,989 283.40 56,267 282.46 0.0526
2016-08-12 2016-06-30 13F AMERICAN TOWER CORP COM 03027X100 129,494 -2,722 -2.06 14,712 8.69 0.0150
2016-05-13 2016-03-31 13F AMERICAN TOWER CORP COM 03027X100 132,216 -86,844 -39.64 13,536 -36.27 0.0152
2016-02-12 2015-12-31 13F AMERICAN TOWER CORP COM 03027X100 219,060 -76,022 -25.76 21,238 -18.19 0.0212
2015-11-13 2015-09-30 13F AMERICAN TOWER CORP COM 03027X100 295,082 -60,015 -16.90 25,961 -21.63 0.0243
2015-08-13 2015-06-30 13F AMERICAN TOWER CORP COM 03027X100 355,097 310 0.09 33,127 -0.83 0.0294
2015-05-14 2015-03-31 13F AMERICAN TOWER CORP COM 03027X100 354,787 -472,317 -57.10 33,403 -59.15 0.0323
2015-02-17 2014-12-31 13F AMERICAN TOWER CORP COM 03027X100 827,104 594,201 255.13 81,760 274.96 0.0730
2014-11-14 2014-09-30 13F AMERICAN TOWER CORP COM 03027X100 232,903 -19,129 -7.59 21,805 -3.85 0.0191
2014-08-14 2014-06-30 13F AMERICAN TOWER CORP COM 03027X100 252,032 -82,065 -24.56 22,677 -17.09 0.0217
2014-05-15 2014-03-31 13F AMERICAN TOWER CORP COM 03027X100 334,097 -176,980 -34.63 27,352 -32.95 0.0280
2014-02-14 2013-12-31 13F AMERICAN TOWER CORP COM 03027X100 511,077 -547,379 -51.71 40,793 -48.01 0.0369
2013-11-14 2013-09-30 13F AMERICAN TOWER CORP COM 03027X100 1,058,456 456,718 75.90 78,463 78.20 0.0735
2013-08-14 2013-06-30 13F AMERICAN TOWER CORP COM 03027X100 601,738 601,738 44,030 0.0434
Disclosed Call Options
File
Date
Effective
Date
Form Security Class ID Opt Avg Share
Price
Shares ΔShares
(%)
Value
(x1000)
ΔValue
(%)
Prior Allocation
(%)
Allocation
(%)
ΔAllocation
(%)
Cost Basis
(x1000)
Profit
(x1000)
Return
(%)
2026-05-11 2026-03-31 13F AMERICAN TOWER COM Call 28,000 -44.00 4,832 -44.95 n/a n/a n/a
2026-02-13 2025-12-31 13F AMERICAN TOWER CORP COM Call 50,000 127.27 8,778 107.47 n/a n/a n/a
2025-11-10 2025-09-30 13F AMERICAN TOWER CORP COM Call 22,000 0.00 4,231 -12.98 n/a n/a n/a
2025-08-11 2025-06-30 13F AMERICAN TOWER CORP COM Call 22,000 0.00 4,862 1.57 n/a n/a n/a
2025-05-12 2025-03-31 13F AMERICAN TOWER CORP COM Call 22,000 4,787 n/a n/a n/a
2022-08-10 2022-06-30 13F AMERICAN TOWER CORP COM Call 0 -100.00 0 -100.00 n/a n/a n/a
2022-05-12 2022-03-31 13F AMERICAN TOWER CORP COM Call 73,000 0.00 18,339 -14.12 n/a n/a n/a
2022-02-10 2021-12-31 13F AMERICAN TOWER CORP COM Call 73,000 508.33 21,353 570.42 n/a n/a n/a
2021-11-10 2021-09-30 13F AMERICAN TOWER CORP COM Call 12,000 0.00 3,185 -1.76 n/a n/a n/a
2021-08-10 2021-06-30 13F AMERICAN TOWER CORP COM Call 12,000 3,242 n/a n/a n/a
2021-05-13 2021-03-31 13F AMERICAN TOWER CORP COM Call 0 -100.00 0 -100.00 n/a n/a n/a
2021-02-11 2020-12-31 13F AMERICAN TOWER CORP COM Call 75,900 -3.68 17,037 -10.56 n/a n/a n/a
2020-11-12 2020-09-30 13F AMERICAN TOWER CORP COM Call 78,800 3.28 19,049 -3.44 n/a n/a n/a
2020-08-12 2020-06-30 13F AMERICAN TOWER CORP COM Call 76,300 -4.86 19,727 12.96 n/a n/a n/a
2020-05-12 2020-03-31 13F AMERICAN TOWER CORP COM Call 80,200 -17.91 17,464 -22.22 n/a n/a n/a
2020-02-12 2019-12-31 13F AMERICAN TOWER CORP COM Call 97,700 -41.43 22,454 -39.12 n/a n/a n/a
2019-11-08 2019-09-30 13F AMERICAN TOWER CORP COM Call 166,800 11.65 36,884 20.76 n/a n/a n/a
2019-08-12 2019-06-30 13F AMERICAN TOWER CORP COM Call 149,400 -47.98 30,544 -46.03 n/a n/a n/a
2019-05-13 2019-03-31 13F AMERICAN TOWER CORP COM Call 287,200 38.41 56,596 72.42 n/a n/a n/a
2019-02-12 2018-12-31 13F AMERICAN TOWER CORP COM Call 207,500 4.11 32,824 13.35 n/a n/a n/a
2018-11-13 2018-09-30 13F AMERICAN TOWER CORP COM Call 199,300 39.76 28,959 40.86 n/a n/a n/a
2018-08-10 2018-06-30 13F AMERICAN TOWER CORP COM Call 142,600 13.72 20,558 12.80 n/a n/a n/a
2018-05-11 2018-03-31 13F AMERICAN TOWER CORP COM Call 125,400 6.54 18,225 8.53 n/a n/a n/a
2018-02-12 2017-12-31 13F AMERICAN TOWER CORP COM Call 117,700 69.60 16,792 77.02 n/a n/a n/a
2017-11-13 2017-09-30 13F AMERICAN TOWER CORP COM Call 69,400 -2.53 9,486 0.69 n/a n/a n/a
2017-08-11 2017-06-30 13F AMERICAN TOWER CORP COM Call 71,200 11.77 9,421 21.69 n/a n/a n/a
2017-05-12 2017-03-31 13F AMERICAN TOWER CORP COM Call 63,700 27.40 7,742 46.52 n/a n/a n/a
2017-02-10 2016-12-31 13F AMERICAN TOWER CORP COM Call 50,000 -13.79 5,284 -19.61 n/a n/a n/a
2016-11-10 2016-09-30 13F AMERICAN TOWER CORP COM Call 58,000 -44.76 6,573 -44.90 n/a n/a n/a
2016-08-12 2016-06-30 13F AMERICAN TOWER CORP COM Call 105,000 9.95 11,929 22.02 n/a n/a n/a
2016-05-13 2016-03-31 13F AMERICAN TOWER CORP COM Call 95,500 -9.31 9,776 -4.24 n/a n/a n/a
2016-02-12 2015-12-31 13F AMERICAN TOWER CORP COM Call 105,300 -38.60 10,209 -32.34 n/a n/a n/a
2015-11-13 2015-09-30 13F AMERICAN TOWER CORP COM Call 171,500 8.54 15,089 2.37 n/a n/a n/a
2015-08-13 2015-06-30 13F AMERICAN TOWER CORP COM Call 158,000 34.58 14,740 33.36 n/a n/a n/a
2015-05-14 2015-03-31 13F AMERICAN TOWER CORP COM Call 117,400 15.21 11,053 9.73 n/a n/a n/a
2015-02-17 2014-12-31 13F AMERICAN TOWER CORP COM Call 101,900 41.92 10,073 49.83 n/a n/a n/a
2014-11-14 2014-09-30 13F AMERICAN TOWER CORP COM Call 71,800 -45.93 6,723 -43.74 n/a n/a n/a
2014-08-14 2014-06-30 13F AMERICAN TOWER CORP COM Call 132,800 -70.59 11,949 -67.67 n/a n/a n/a
2014-05-15 2014-03-31 13F AMERICAN TOWER CORP COM Call 451,500 65.99 36,965 70.26 n/a n/a n/a
2014-02-14 2013-12-31 13F AMERICAN TOWER CORP COM Call 272,000 -49.14 21,711 -45.24 n/a n/a n/a
2013-11-14 2013-09-30 13F AMERICAN TOWER CORP COM Call 534,800 5.38 39,645 6.76 n/a n/a n/a
2013-08-14 2013-06-30 13F AMERICAN TOWER CORP COM Call 507,500 37,133 n/a n/a n/a
Disclosed Put Options
File
Date
Effective
Date
Form Security Class ID Opt Avg Share Price Shares ΔShares
(%)
Value
(x1000)
ΔValue
(%)
Prior Allocation
(%)
Allocation
(%)
ΔAllocation
(%)
Cost Basis
(x1000)
Profit
(x1000)
Return
(%)
2026-05-11 2026-03-31 13F AMERICAN TOWER COM Put 42,000 -50.00 7,248 -50.85 n/a n/a n/a
2026-02-13 2025-12-31 13F AMERICAN TOWER CORP COM Put 84,000 100.00 14,748 82.58 n/a n/a n/a
2025-11-10 2025-09-30 13F AMERICAN TOWER CORP COM Put 42,000 0.00 8,077 -12.98 n/a n/a n/a
2025-08-11 2025-06-30 13F AMERICAN TOWER CORP COM Put 42,000 27.27 9,283 29.28 n/a n/a n/a
2025-05-12 2025-03-31 13F AMERICAN TOWER CORP COM Put 33,000 7,181 n/a n/a n/a
2022-08-10 2022-06-30 13F AMERICAN TOWER CORP COM Put 0 -100.00 0 -100.00 n/a n/a n/a
2022-05-12 2022-03-31 13F AMERICAN TOWER CORP COM Put 147,200 -14.02 36,980 -26.15 n/a n/a n/a
2022-02-10 2021-12-31 13F AMERICAN TOWER CORP COM Put 171,200 678.18 50,076 757.61 n/a n/a n/a
2021-11-10 2021-09-30 13F AMERICAN TOWER CORP COM Put 22,000 22.22 5,839 20.07 n/a n/a n/a
2021-08-10 2021-06-30 13F AMERICAN TOWER CORP COM Put 18,000 4,863 n/a n/a n/a
2021-05-13 2021-03-31 13F AMERICAN TOWER CORP COM Put 0 -100.00 0 -100.00 n/a n/a n/a
2021-02-11 2020-12-31 13F AMERICAN TOWER CORP COM Put 89,700 -17.86 20,135 -23.72 n/a n/a n/a
2020-11-12 2020-09-30 13F AMERICAN TOWER CORP COM Put 109,200 -18.02 26,396 -23.35 n/a n/a n/a
2020-08-12 2020-06-30 13F AMERICAN TOWER CORP COM Put 133,200 29.70 34,437 53.99 n/a n/a n/a
2020-05-12 2020-03-31 13F AMERICAN TOWER CORP COM Put 102,700 -58.10 22,363 -60.30 n/a n/a n/a
2020-02-12 2019-12-31 13F AMERICAN TOWER CORP COM Put 245,100 22.73 56,329 27.56 n/a n/a n/a
2019-11-08 2019-09-30 13F AMERICAN TOWER CORP COM Put 199,700 -20.85 44,160 -14.39 n/a n/a n/a
2019-08-12 2019-06-30 13F AMERICAN TOWER CORP COM Put 252,300 -9.44 51,583 -6.04 n/a n/a n/a
2019-05-13 2019-03-31 13F AMERICAN TOWER CORP COM Put 278,600 -20.58 54,901 -1.07 n/a n/a n/a
2019-02-12 2018-12-31 13F AMERICAN TOWER CORP COM Put 350,800 48.64 55,493 61.83 n/a n/a n/a
2018-11-13 2018-09-30 13F AMERICAN TOWER CORP COM Put 236,000 31.33 34,291 32.36 n/a n/a n/a
2018-08-10 2018-06-30 13F AMERICAN TOWER CORP COM Put 179,700 21.75 25,907 20.77 n/a n/a n/a
2018-05-11 2018-03-31 13F AMERICAN TOWER CORP COM Put 147,600 -22.32 21,452 -20.86 n/a n/a n/a
2018-02-12 2017-12-31 13F AMERICAN TOWER CORP COM Put 190,000 30.67 27,107 36.40 n/a n/a n/a
2017-11-13 2017-09-30 13F AMERICAN TOWER CORP COM Put 145,400 0.48 19,873 3.79 n/a n/a n/a
2017-08-11 2017-06-30 13F AMERICAN TOWER CORP COM Put 144,700 138.78 19,147 159.97 n/a n/a n/a
2017-05-12 2017-03-31 13F AMERICAN TOWER CORP COM Put 60,600 -18.98 7,365 -6.83 n/a n/a n/a
2017-02-10 2016-12-31 13F AMERICAN TOWER CORP COM Put 74,800 -26.81 7,905 -31.75 n/a n/a n/a
2016-11-10 2016-09-30 13F AMERICAN TOWER CORP COM Put 102,200 47.90 11,582 47.52 n/a n/a n/a
2016-08-12 2016-06-30 13F AMERICAN TOWER CORP COM Put 69,100 -5.34 7,851 5.06 n/a n/a n/a
2016-05-13 2016-03-31 13F AMERICAN TOWER CORP COM Put 73,000 53.04 7,473 61.58 n/a n/a n/a
2016-02-12 2015-12-31 13F AMERICAN TOWER CORP COM Put 47,700 -47.70 4,625 -42.36 n/a n/a n/a
2015-11-13 2015-09-30 13F AMERICAN TOWER CORP COM Put 91,200 -51.85 8,024 -54.59 n/a n/a n/a
2015-08-13 2015-06-30 13F AMERICAN TOWER CORP COM Put 189,400 123.88 17,669 121.83 n/a n/a n/a
2015-05-14 2015-03-31 13F AMERICAN TOWER CORP COM Put 84,600 -44.56 7,965 -47.20 n/a n/a n/a
2015-02-17 2014-12-31 13F AMERICAN TOWER CORP COM Put 152,600 3.95 15,084 9.74 n/a n/a n/a
2014-11-14 2014-09-30 13F AMERICAN TOWER CORP COM Put 146,800 -5.84 13,745 -2.02 n/a n/a n/a
2014-08-14 2014-06-30 13F AMERICAN TOWER CORP COM Put 155,900 -69.57 14,028 -66.56 n/a n/a n/a
2014-05-15 2014-03-31 13F AMERICAN TOWER CORP COM Put 512,400 79.16 41,950 83.77 n/a n/a n/a
2014-02-14 2013-12-31 13F AMERICAN TOWER CORP COM Put 286,000 -57.58 22,828 -54.32 n/a n/a n/a
2013-11-14 2013-09-30 13F AMERICAN TOWER CORP COM Put 674,200 60.52 49,979 62.63 n/a n/a n/a
2013-08-14 2013-06-30 13F AMERICAN TOWER CORP COM Put 420,000 30,732 n/a n/a n/a
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.