TransAlta Corporation
US ˙ NYSE ˙ CA89346D1078

SecurityTAC / TransAlta Corporation
InstitutionCitadel Advisors Llc
ManagerKen Griffin
Latest Disclosed Ownership1,632,890 shares
Latest Disclosed Value $ 21,390,859
Citadel Advisors Llc ownership in TAC / TransAlta Corporation

On May 15, 2026 - Citadel Advisors Llc filed a 13F-HR form disclosing ownership of 1,632,890 shares of TransAlta Corporation (US:TAC) valued at $21,390,859 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 17, 2026 disclosing 2,027,408 shares of TransAlta Corporation. This represents a change in shares of -19.46% during the quarter. The current value of the position is $20,705,045 USD.

Citadel Advisors Llc has a history of taking positions in derivatives of the underlying security (TAC) in the form of stock options. The firm currently holds call options representing 132,400 of underlying shares valued at $1,734,440 USD and put options representing 39,300 of underlying shares valued at $514,830 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.

TAC / TransAlta 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)
2026-05-15 2026-03-31 13F TRANSALTA COM 89346D107 1,632,890 -394,518 -19.46 21,391 -16.53 0.0030
2026-02-17 2025-12-31 13F TRANSALTA COM 89346D107 2,027,408 1,056,088 108.73 25,626 93.01 0.0038
2025-11-14 2025-09-30 13F TRANSALTA COM 89346D107 971,320 -319,991 -24.78 13,278 -4.71 0.0020
2025-08-14 2025-06-30 13F TRANSALTA COM 89346D107 1,291,311 1,284,093 17,790.15 13,933 20,695.52 0.0024
2025-05-15 2025-03-31 13F TRANSALTA COM 89346D107 7,218 -191,570 -96.37 67 -97.62 0.0000
2025-02-14 2024-12-31 13F TRANSALTA COM 89346D107 198,788 -416,313 -67.68 2,813 -55.87 0.0005
2024-11-14 2024-09-30 13F TRANSALTA COM 89346D107 615,101 79,385 14.82 6,372 68.04 0.0012
2024-08-14 2024-06-30 13F TRANSALTA COM 89346D107 535,716 140,305 35.48 3,793 49.17 0.0008
2024-05-15 2024-03-31 13F TRANSALTA COM 89346D107 395,411 251,094 173.99 2,542 112.01 0.0005
2024-02-14 2023-12-31 13F TRANSALTA COM 89346D107 144,317 -60,848 -29.66 1,199 -32.79 0.0002
2023-11-14 2023-09-30 13F TRANSALTA COM 89346D107 205,165 -161,088 -43.98 1,785 -47.96 0.0004
2023-08-14 2023-06-30 13F TRANSALTA COM 89346D107 366,253 -322,585 -46.83 3,428 -43.12 0.0007
2023-05-15 2023-03-31 13F TRANSALTA COM 89346D107 688,838 106,460 18.28 6,027 15.39 0.0013
2023-02-14 2022-12-31 13F TRANSALTA COM 89346D107 582,378 560,940 2,616.57 5,224 2,663.49 0.0012
2022-11-14 2022-09-30 13F TRANSALTA COM 89346D107 21,438 1,567 7.89 189 -16.74 0.0000
2022-08-15 2022-06-30 13F TRANSALTA COM 89346D107 19,871 -100,887 -83.54 227 -81.85 0.0001
2022-05-16 2022-03-31 13F TRANSALTA COM 89346D107 120,758 -159,197 -56.87 1,251 -59.81 0.0003
2022-02-14 2021-12-31 13F TRANSALTA COM 89346D107 279,955 74,988 36.59 3,113 43.85 0.0006
2021-11-15 2021-09-30 13F TRANSALTA Cmn 89346D107 204,967 113,627 124.40 2,164 137.28 0.0004
2021-08-16 2021-06-30 13F TRANSALTA COM 89346D107 91,340 54,036 144.85 912 158.36 0.0002
2021-05-21 2021-03-31 13F/A-1 TRANSALTA COM 89346D107 37,304 -187,412 -83.40 353 -79.30 0.0001
2021-05-17 2021-03-31 13F TRANSALTA COM 89346D107 37,304 -187,412 353 0.0001
2021-02-16 2020-12-31 13F TRANSALTA COM 89346D107 224,716 -164,041 -42.20 1,705 -28.69 0.0004
2020-11-16 2020-09-30 13F TRANSALTA COM 89346D107 388,757 -179,094 -31.54 2,391 -28.99 0.0007
2020-08-14 2020-06-30 13F TRANSALTA Cmn 89346D107 567,851 -13,902 -2.39 3,367 10.47 0.0012
2020-05-15 2020-03-31 13F TRANSALTA Cmn 89346D107 581,753 284,305 95.58 3,048 43.23 0.0014
2020-02-14 2019-12-31 13F TRANSALTA Cmn 89346D107 297,448 68,818 30.10 2,128 43.11 0.0009
2019-11-14 2019-09-30 13F TRANSALTA Cmn 89346D107 228,630 -14,310 -5.89 1,487 -6.01 0.0007
2019-08-14 2019-06-30 13F TRANSALTA Cmn 89346D107 242,940 161,616 198.73 1,582 165.44 0.0007
2019-05-15 2019-03-31 13F TRANSALTA Cmn 89346D107 81,324 -116,673 -58.93 596 -26.60 0.0003
2019-02-14 2018-12-31 13F TRANSALTA Cmn 89346D107 197,997 187,349 1,759.48 812 1,253.33 0.0004
2018-11-13 2018-09-30 13F TRANSALTA Cmn 89346D107 10,648 -30,748 -74.28 60 -71.01 0.0000
2018-08-14 2018-06-30 13F/A-1 TRANSALTA Cmn 89346D107 41,396 24,359 142.98 207 122.58 0.0001
2018-08-10 2018-06-30 13F TRANSALTA Cmn 89346D107 41,396 24,359 207
2018-05-14 2018-03-31 13F/A-1 TRANSALTA Cmn 89346D107 17,037 4,622 37.23 93 25.68 0.0001
2018-05-11 2018-03-31 13F TRANSALTA Cmn 89346D107 17,037 4,622 93
2018-02-09 2017-12-31 13F TRANSALTA Cmn 89346D107 12,415 -6,685 -35.00 74 -33.93 0.0000
2017-11-09 2017-09-30 13F TRANSALTA Cmn 89346D107 19,100 -5,100 -21.07 112 -10.40 0.0001
2017-01-31 2016-06-30 13F/A-1 TRANSALTA Cmn 89346D107 24,200 9,658 66.41 125 83.82 0.0001
2016-08-12 2016-06-30 13F TRANSALTA Cmn 89346D107 24,200 125
2017-01-31 2016-03-31 13F/A-1 TRANSALTA Cmn 89346D107 14,542 -14,799 -50.44 68 -50.00 0.0001
2016-05-13 2016-03-31 13F TRANSALTA Cmn 89346D107 14,542 68
2015-11-16 2015-09-30 13F TRANSALTA Cmn 89346D107 29,341 -7,148 -19.59 136 -59.88 0.0001
2015-05-15 2015-03-31 13F TRANSALTA Cmn 89346D107 36,489 13,782 60.69 339 65.37 0.0004
2015-02-17 2014-12-31 13F TRANSALTA Cmn 89346D107 22,707 -1,570 -6.47 205 -31.21 0.0002
2014-08-14 2014-06-30 13F TRANSALTA Cmn 89346D107 24,277 24,277 298 0.0004
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
(%)
2026-05-15 2026-03-31 13F TRANSALTA COM Call 132,400 72.17 1,734 78.40 n/a n/a n/a
2026-02-17 2025-12-31 13F TRANSALTA COM Call 76,900 7.40 972 -0.61 n/a n/a n/a
2025-11-14 2025-09-30 13F TRANSALTA COM Call 71,600 -25.49 979 -5.60 n/a n/a n/a
2025-08-14 2025-06-30 13F TRANSALTA COM Call 96,100 16.20 1,037 34.02 n/a n/a n/a
2025-05-15 2025-03-31 13F TRANSALTA COM Call 82,700 25.11 773 -17.33 n/a n/a n/a
2025-02-14 2024-12-31 13F TRANSALTA COM Call 66,100 1,473.81 935 2,074.42 n/a n/a n/a
2024-11-14 2024-09-30 13F TRANSALTA COM Call 4,200 40.00 44 104.76 n/a n/a n/a
2024-08-14 2024-06-30 13F TRANSALTA COM Call 3,000 -92.59 21 -91.92 n/a n/a n/a
2024-05-15 2024-03-31 13F TRANSALTA COM Call 40,500 965.79 260 738.71 n/a n/a n/a
2024-02-14 2023-12-31 13F TRANSALTA COM Call 3,800 -84.36 32 -85.31 n/a n/a n/a
2023-11-14 2023-09-30 13F TRANSALTA COM Call 24,300 -62.38 211 -65.07 n/a n/a n/a
2023-08-14 2023-06-30 13F TRANSALTA COM Call 64,600 -58.98 605 -56.17 n/a n/a n/a
2023-05-15 2023-03-31 13F TRANSALTA COM Call 157,500 78,650.00 1,378 137,700.00 n/a n/a n/a
2023-02-14 2022-12-31 13F TRANSALTA COM Call 200 -99.66 2 -99.80 n/a n/a n/a
2022-11-14 2022-09-30 13F TRANSALTA COM Call 58,000 -23.98 512 -41.15 n/a n/a n/a
2022-08-15 2022-06-30 13F TRANSALTA COM Call 76,300 441.13 870 483.89 n/a n/a n/a
2021-11-15 2021-09-30 13F TRANSALTA Cmn Call 14,100 36.89 149 44.66 n/a n/a n/a
2021-08-16 2021-06-30 13F TRANSALTA COM Call 10,300 103 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
(%)
2026-05-15 2026-03-31 13F TRANSALTA COM Put 39,300 -86.09 515 -85.60 n/a n/a n/a
2026-02-17 2025-12-31 13F TRANSALTA COM Put 282,500 1,514.29 3,571 1,393.72 n/a n/a n/a
2025-11-14 2025-09-30 13F TRANSALTA COM Put 17,500 -73.92 239 -66.99 n/a n/a n/a
2025-08-14 2025-06-30 13F TRANSALTA COM Put 67,100 -0.74 724 14.56 n/a n/a n/a
2025-05-15 2025-03-31 13F TRANSALTA COM Put 67,600 317.28 632 175.98 n/a n/a n/a
2025-02-14 2024-12-31 13F TRANSALTA COM Put 16,200 -38.40 229 -15.81 n/a n/a n/a
2024-11-14 2024-09-30 13F TRANSALTA COM Put 26,300 -7.07 272 36.00 n/a n/a n/a
2024-08-14 2024-06-30 13F TRANSALTA COM Put 28,300 32.24 200 45.99 n/a n/a n/a
2024-05-15 2024-03-31 13F TRANSALTA COM Put 21,400 1,845.45 138 1,422.22 n/a n/a n/a
2024-02-14 2023-12-31 13F TRANSALTA COM Put 1,100 -92.25 9 -92.68 n/a n/a n/a
2023-11-14 2023-09-30 13F TRANSALTA COM Put 14,200 -44.96 124 -48.96 n/a n/a n/a
2023-08-14 2023-06-30 13F TRANSALTA COM Put 25,800 -44.28 241 -40.49 n/a n/a n/a
2023-05-15 2023-03-31 13F TRANSALTA COM Put 46,300 2,623.53 405 2,600.00 n/a n/a n/a
2023-02-14 2022-12-31 13F TRANSALTA COM Put 1,700 -98.77 15 -98.78 n/a n/a n/a
2022-11-14 2022-09-30 13F TRANSALTA COM Put 138,700 116.38 1,225 67.58 n/a n/a n/a
2022-08-15 2022-06-30 13F TRANSALTA COM Put 64,100 389.31 731 437.50 n/a n/a n/a
2022-05-16 2022-03-31 13F TRANSALTA COM Put 13,100 -25.14 136 -26.49 n/a n/a n/a
2021-11-15 2021-09-30 13F TRANSALTA Cmn Put 17,500 -24.57 185 -20.26 n/a n/a n/a
2021-08-16 2021-06-30 13F TRANSALTA COM Put 23,200 232 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.