TransAlta Corporation TAC

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TransAlta Corporation Ordinary Shares · Company · NYSE

Announcement types: (default: consequential filings)
Results & current reports
Capital markets
Ownership & governance

USD closing-price chart (daily close from yfinance · Last year)

USD 12.29 → 14.04 · 14.2%
17.73014.75511.780 1 2,3 4 5 6 7,8,9 10 11,12 13,14,15 16 17 18 19 20,21,22,23,24 25 26,27 28 29 30 31 32 33,34 35,36 37 38 39,40 41 42 Jul 25Oct 25Jan 26Apr 26Jul 26

Numbered dotted lines mark the filtered filings under Announcement Events below.

Price & SEC Filing History 22 Jul 2025 — 23 Jul 2026 (Last year)

Daily NYSE prices are sourced from yfinance. Yellow highlighting marks an intraday rise or a gap up between adjacent trading sessions. SEC acceptance times are converted to US Eastern time: pre-market filings appear below that day’s OHLCV row; filings accepted after the 09:30 ET open appear above it. The SEC does not publish an exact first-public-availability timestamp, so acceptance time is the best available proxy.

No data yet
14.0000 14.1200 13.6600 14.0400 743,731
13.9100 14.0200 13.6900 13.9900 1,392,600
13.3700 13.7500 13.2700 13.7200 1,200,800
Weekend
Weekend
13.1400 13.4500 13.0500 13.2600 1,274,000
13.5400 13.6400 13.1500 13.2400 745,600
13.8900 14.0400 13.4800 13.6200 1,277,700
13.9300 14.1900 13.8700 13.9300 1,657,600
14.2300 14.2600 13.8700 13.9300 920,200
Weekend
Weekend
14.4900 14.5100 14.2200 14.2200 1,148,100
14.5800 14.8500 14.3000 14.5200 1,447,800
14.0000 14.5500 13.9700 14.4800 2,191,200
13.5400 14.0900 13.5300 14.0600 1,409,200
13.7200 13.9700 13.5500 13.6100 1,642,700
Weekend
Weekend
No trading
13.7300 13.8400 13.3100 13.4700 2,793,600
13.6700 13.8600 13.5200 13.6000 888,900
42 · 6-K After-hours · 16:36 ET FORM 6-K ↗
13.4800 13.9400 13.4800 13.8300 2,348,400
13.8500 13.8800 13.4700 13.6200 1,887,600
Weekend
Weekend
13.6600 13.8800 13.6600 13.8000 968,700
13.8900 13.9800 13.5900 13.8100 1,435,900
13.5900 13.9300 13.5100 13.6900 1,569,900
13.5600 13.7300 13.5200 13.6900 1,104,200
13.7900 14.0600 13.7000 13.8500 1,208,700
Weekend
Weekend
No trading
13.7700 13.8500 13.5100 13.7400 1,720,700
13.4700 13.8800 13.4600 13.5600 1,742,700
13.5500 13.6800 13.4500 13.5100 1,726,200
13.4000 13.6600 13.3200 13.5700 1,186,800
41 · 6-K Pre-market · 07:12 ET FORM 6-K ↗
Weekend
Weekend
13.3600 13.6500 13.2700 13.3900 3,561,500
12.4400 13.4800 12.4000 13.3700 2,441,000
12.7800 12.7800 12.1700 12.3800 3,210,100
40 · 6-K After-hours · 16:00 ET 6-K ↗
12.5100 12.8300 12.3400 12.4600 2,512,500
39 · 6-K Pre-market · 09:20 ET FORM 6-K ↗
12.6900 12.8200 12.4100 12.5100 3,245,300
Weekend
Weekend
38 · 6-K After-hours · 16:18 ET 6-K ↗
12.9500 13.1300 12.4700 12.6800 2,044,400
13.6100 13.6200 12.7000 12.9600 4,257,000
37 · 6-K Next filing day · accepted 03 Jun, 20:33 ET 6-K ↗
14.4500 14.7700 14.3100 14.4600 1,459,200
14.2200 14.6100 14.1700 14.3400 1,696,500
14.0200 14.3600 13.9200 14.1600 3,653,400
Weekend
Weekend
14.0100 14.2500 13.8300 14.2200 991,600
13.8400 14.1000 13.7800 14.0300 709,000
14.0800 14.0800 13.7600 13.8200 739,900
13.7400 14.2300 13.7100 14.1200 963,200
No trading
Weekend
Weekend
13.5600 13.8200 13.4200 13.5700 4,604,900
12.8900 13.5000 12.8800 13.5000 950,800
12.9600 13.0600 12.8100 12.9800 1,110,600
12.5900 13.0800 12.4800 12.8600 1,217,600
12.7600 12.8500 12.3400 12.4600 545,100
Weekend
Weekend
12.7200 12.9300 12.6200 12.7800 950,000
12.7400 13.0700 12.6000 12.9500 617,300
12.5900 12.8300 12.5000 12.7300 659,900
12.6200 12.6900 12.2900 12.5800 1,089,400
12.7700 12.9700 12.7100 12.8000 1,321,700
Weekend
Weekend
12.7800 12.8800 12.5200 12.7600 1,448,400
12.8800 12.8800 12.3900 12.7600 1,361,900
12.7100 13.1900 12.4000 12.7900 2,791,100
36 · 6-K Pre-market · 07:02 ET 6-K ↗ 35 · 6-K Pre-market · 07:02 ET 6-K ↗
12.6900 12.7300 12.4400 12.6000 923,200
12.4800 12.6200 12.3600 12.6200 1,299,700
Weekend
Weekend
12.4900 12.6400 12.4000 12.4800 1,229,200
34 · 6-K Next filing day · accepted 30 Apr, 18:49 ET FORM 6-K ↗ 33 · 6-K Next filing day · accepted 30 Apr, 18:45 ET 6-K ↗
12.0900 12.5600 12.0800 12.4800 1,969,000
32 · 6-K Next filing day · accepted 29 Apr, 17:33 ET FORM 6-K ↗
12.6900 12.7800 11.9400 12.0100 1,510,800
12.4900 12.8600 12.4500 12.7100 1,482,400
12.6300 12.7000 12.4100 12.5900 1,558,600
Weekend
Weekend
12.1200 12.5500 11.9900 12.4900 1,231,000
12.3300 12.5400 11.9200 12.0800 890,500
12.3100 12.3800 12.0200 12.2800 806,200
12.4500 12.7000 12.1300 12.1600 1,066,500
12.6500 12.7800 12.5400 12.6600 1,207,100
31 · 6-K Pre-market · 07:05 ET FORM 6-K ↗
Weekend
Weekend
13.5000 13.5000 12.6500 12.6600 1,829,400
13.6600 13.6800 13.3600 13.5000 607,500
13.4600 13.9000 13.3200 13.6800 1,474,700
13.5600 13.7900 13.4300 13.4900 758,400
13.9400 13.9900 13.6600 13.6800 581,100
Weekend
Weekend
13.8800 14.1200 13.8700 14.0000 555,400
13.8000 14.2400 13.7500 13.8300 982,100
13.9300 14.0600 13.5700 13.8300 957,600
30 · 6-K After-hours · 17:01 ET FORM 6-K ↗
13.5800 13.7900 13.3900 13.5400 1,000,200
13.4100 13.7200 13.4100 13.6400 1,168,700
Weekend
Weekend
No trading
13.0500 13.4900 13.0300 13.4800 853,100
13.2000 13.4700 13.1500 13.2900 1,309,600
29 · 6-K After market open · 12:10 ET 6-K ↗
12.9000 13.2500 12.8100 13.1000 1,679,700
13.0500 13.0500 12.6100 12.7100 1,254,500
Weekend
Weekend
12.9400 13.0800 12.8000 12.9200 2,231,700
12.9800 13.2100 12.8700 12.9400 1,217,200
13.0000 13.3000 12.9400 13.0600 2,211,800
12.3700 12.9300 12.0600 12.7600 2,283,700
11.8600 12.1000 11.3800 12.0300 2,142,000
28 · 6-K Pre-market · 07:25 ET FORM 6-K ↗
Weekend
Weekend
12.2800 12.4100 11.6900 11.7800 3,042,800
12.3000 12.5600 12.1600 12.4100 2,363,000
12.6100 12.6500 12.4200 12.4400 1,115,800
27 · 6-K After-hours · 17:10 ET FORM 6-K ↗ 26 · 6-K After-hours · 17:10 ET FORM 6-K ↗
12.4700 12.6600 12.4000 12.5500 1,508,600
12.5900 12.6700 12.3000 12.4700 1,237,900
Weekend
Weekend
12.8200 13.0400 12.4000 12.4400 1,003,200
12.7000 13.0700 12.5900 12.7600 1,627,800
12.7500 12.9500 12.5900 12.8600 1,284,700
12.7000 12.9600 12.6400 12.7300 2,210,400
12.6000 12.6900 12.1100 12.6500 2,527,000
Weekend
Weekend
13.0500 13.1700 12.6100 12.7200 1,414,700
13.1400 13.3100 12.9900 13.2900 959,200
13.2700 13.6300 13.1500 13.2500 1,009,200
13.4700 13.6300 12.9500 13.2700 1,995,100
25 · 6-K After-hours · 17:18 ET FORM 6-K ↗
13.5500 14.2000 13.2600 13.8100 1,814,500
Weekend
Weekend
13.3200 14.0100 13.2600 13.7400 3,089,500
24 · 6-K Pre-market · 07:37 ET FORM 6-K ↗ 23 · 6-K Pre-market · 07:35 ET FORM 6-K ↗ 22 · 6-K Pre-market · 07:06 ET 6-K ↗ 21 · 6-K Pre-market · 07:05 ET 6-K ↗ 20 · 40-F Pre-market · 07:04 ET 40-F ↗
12.8600 13.0300 12.5900 13.0300 2,645,200
13.0900 13.1200 12.8500 12.8600 1,133,100
12.9600 13.1300 12.8700 13.0400 1,130,700
13.4800 13.5000 12.7600 12.9000 1,231,300
Weekend
Weekend
13.4700 13.5500 13.2600 13.5000 725,400
13.4500 13.6000 13.2700 13.4800 664,900
13.5000 13.5600 13.3000 13.3900 1,265,000
13.5300 13.6300 13.2100 13.4300 1,505,900
No trading
Weekend
Weekend
13.3100 13.6700 13.2900 13.5800 805,200
13.5700 13.6800 12.9900 13.3400 934,600
13.4400 13.5400 13.0400 13.5400 894,800
13.6000 13.6000 13.0200 13.2500 1,082,900
13.3500 13.6200 13.2200 13.6100 1,639,700
Weekend
Weekend
12.5700 13.2500 12.5500 13.2400 1,770,200
12.4800 12.6100 12.3100 12.3600 1,720,500
13.1300 13.2200 12.5400 12.5900 1,956,700
12.9500 13.2400 12.8200 13.0700 2,006,400
12.7200 12.9900 12.6300 12.7600 1,239,700
Weekend
Weekend
13.3100 13.5700 12.6800 12.7800 1,796,500
13.9800 13.9900 13.3700 13.5500 2,283,000
13.8600 13.9800 13.6900 13.9400 2,714,600
19 · 6-K Next filing day · accepted 27 Jan, 21:00 ET FORM 6-K ↗
12.8900 13.8700 12.8800 13.8100 3,754,300
12.7900 13.2200 12.7500 12.8500 1,447,900
Weekend
Weekend
12.5000 12.8200 12.3800 12.7000 913,800
12.5200 12.9300 12.4700 12.4700 1,605,800
13.1000 13.3700 12.0800 12.3600 2,673,500
12.4000 12.9200 12.3400 12.9200 2,616,400
No trading
Weekend
Weekend
12.3500 12.5600 12.0200 12.5600 2,631,300
12.3100 12.4200 11.9600 12.3500 842,200
12.1500 12.2000 11.9700 12.1000 1,218,500
12.2100 12.2700 12.0900 12.1700 1,176,400
12.3500 12.4100 12.1800 12.1800 1,182,700
Weekend
Weekend
12.5500 12.6300 12.3500 12.3700 1,329,000
12.2800 12.4000 12.1000 12.2000 770,700
12.7300 12.8200 12.2800 12.3300 1,059,200
12.9600 12.9600 12.4700 12.7200 1,366,400
13.0300 13.1300 12.5900 12.8700 1,318,500
Weekend
Weekend
12.7900 13.0400 12.7100 13.0200 1,164,700
No trading
12.6700 12.8000 12.6200 12.6400 709,400
12.7200 12.8100 12.6400 12.6600 1,232,600
12.7600 12.8600 12.6300 12.7200 1,066,900
Weekend
Weekend
12.7300 12.9300 12.6400 12.8400 570,400
No trading
12.6800 12.7400 12.5100 12.7300 708,200
12.4600 12.7300 12.4500 12.7100 910,000
18 · 6-K After-hours · 16:27 ET 6-K ↗
12.6300 12.6300 12.3400 12.4600 1,550,400
Weekend
Weekend
12.5800 12.9200 12.4900 12.5300 2,422,300
17 · 6-K After-hours · 17:30 ET FORM 6-K ↗
13.0100 13.1000 12.5000 12.5700 2,132,600
13.6500 13.6800 12.7300 12.8100 2,190,700
16 · 6-K Pre-market · 09:01 ET FORM 6-K ↗
13.5200 13.7600 13.5200 13.5800 929,300
15 · 6-K After-hours · 17:23 ET 6-K ↗
14.0700 14.0700 13.5400 13.6900 1,227,400
14 · 6-K Next filing day · accepted 12 Dec, 18:41 ET 6-K ↗ 13 · 6-K Next filing day · accepted 12 Dec, 18:46 ET FORM 6-K ↗
Weekend
Weekend
14.5400 14.5400 13.8400 13.8500 1,095,700
14.4000 14.5500 14.0700 14.4200 1,403,700
14.7300 14.8600 14.1500 14.4600 1,829,200
11 · 6-K After-hours · 16:53 ET FORM 6-K ↗
14.2500 15.2400 14.2500 14.6100 1,828,300
12 · F-10EF Pre-market · 09:22 ET F-10EF ↗
14.1600 14.1700 13.8800 14.1100 1,052,400
Weekend
Weekend
14.2800 14.3800 13.9700 14.0600 784,900
14.0100 14.4200 13.9200 14.2600 993,000
14.0700 14.1500 13.9100 14.0000 699,900
14.3800 14.4400 14.0300 14.0600 1,262,500
14.2900 14.3800 14.1200 14.2400 1,445,400
Weekend
Weekend
14.1700 14.5900 14.0400 14.5500 782,200
No trading
14.1400 14.2100 13.8900 14.0600 889,000
14.0800 14.1700 13.6800 14.0000 1,446,200
13.8500 14.2300 13.7500 14.1900 2,055,900
Weekend
Weekend
13.8100 13.9500 13.2900 13.7000 2,327,700
14.7600 14.9200 13.7800 13.8400 1,995,800
14.5400 14.6800 14.3700 14.4800 1,672,100
14.1700 14.6500 14.1100 14.4200 1,365,300
14.6500 14.8800 14.0100 14.2400 2,063,900
10 · 6-K Pre-market · 06:30 ET FORM 6-K ↗
Weekend
Weekend
14.2100 14.9300 14.1100 14.5800 1,540,400
15.1600 15.1600 14.1500 14.4100 3,635,900
15.6000 15.6500 15.2500 15.2600 1,238,200
15.7600 15.9100 15.4700 15.5300 1,326,000
15.8200 15.9800 15.4900 15.7700 2,227,900
Weekend
Weekend
14.5600 15.8000 13.9200 15.5100 4,135,600
13.8100 15.1500 13.5200 14.9400 9,347,500
9 · 6-K Pre-market · 07:46 ET FORM 6-K ↗ 8 · 6-K Pre-market · 07:06 ET 6-K ↗ 7 · 6-K Pre-market · 07:04 ET 6-K ↗
16.8700 17.0600 16.6700 16.8700 2,259,300
17.2300 17.4800 16.5500 16.6800 1,865,300
17.6300 17.8100 17.4800 17.6200 1,437,400
Weekend
Weekend
17.6700 17.8200 17.4500 17.6700 995,900
17.5800 17.8200 17.4900 17.6400 1,558,000
17.2600 17.8800 17.0400 17.7300 1,728,700
17.2000 17.3200 16.7800 17.1500 2,066,400
17.4200 17.4900 16.7600 17.0000 1,521,900
Weekend
Weekend
17.5200 17.5200 17.0300 17.2700 1,544,800
16.7500 17.3700 16.7000 17.2300 2,107,400
6 · 6-K After-hours · 16:49 ET FORM 6-K ↗
16.7000 17.2100 16.2400 16.7300 2,385,200
16.8000 16.9200 16.4500 16.7100 1,607,200
16.7200 17.1000 16.5900 16.8600 2,472,200
Weekend
Weekend
16.6300 16.9000 16.1800 16.5700 2,652,900
17.1500 17.1500 16.5800 16.9600 2,212,400
17.0500 17.3500 16.9300 17.0400 2,777,600
16.8700 16.9200 16.1700 16.7300 4,305,100
16.3300 17.6900 16.2100 17.1000 6,896,000
Weekend
Weekend
15.6700 16.2000 15.5500 15.5900 4,124,700
15.6000 15.7900 15.4100 15.6000 1,332,200
5 · 6-K After-hours · 16:39 ET FORM 6-K ↗
15.0700 15.7000 15.0500 15.6100 3,095,700
14.7100 15.0100 14.5800 15.0000 1,211,300
14.5000 14.8600 14.4700 14.6700 2,025,700
Weekend
Weekend
13.7700 14.9000 13.5200 14.4700 3,363,600
13.9000 13.9100 13.6600 13.7000 1,256,600
13.6900 13.9100 13.6400 13.8000 3,655,100
13.6100 13.7900 13.5800 13.6700 836,000
13.6600 13.7600 13.5600 13.6700 466,800
Weekend
Weekend
13.5300 13.6400 13.4500 13.6200 526,900
13.5000 13.5500 13.4000 13.4900 741,100
13.6800 13.7400 13.4600 13.6400 616,300
13.8300 13.8300 13.5900 13.6200 670,500
13.5100 13.9000 13.4700 13.8600 1,811,300
Weekend
Weekend
13.6800 13.8100 13.2600 13.6400 1,695,900
4 · 6-K After-hours · 17:09 ET FORM 6-K ↗
13.2800 13.5900 13.1800 13.4700 1,413,900
12.8800 13.2700 12.8300 13.1400 1,221,400
13.0000 13.0000 12.7700 12.9300 488,100
12.6400 13.0200 12.6400 13.0000 1,714,800
Weekend
Weekend
12.5600 12.6700 12.5300 12.6400 699,800
12.7100 12.8200 12.4500 12.6500 947,900
12.4700 12.7300 12.4400 12.6800 705,300
12.3000 12.5300 12.2500 12.3500 918,200
12.3200 12.3700 12.1600 12.3100 1,131,100
Weekend
Weekend
12.2300 12.2900 12.0400 12.2800 524,700
12.0600 12.1300 11.9400 12.1200 1,629,500
12.0600 12.1200 12.0100 12.0400 725,700
12.1100 12.2800 11.9500 12.1000 567,800
No trading
Weekend
Weekend
12.5200 12.5200 12.2200 12.3000 2,152,000
12.1300 12.6600 12.0800 12.6100 704,700
12.2000 12.2700 12.0200 12.0700 490,700
12.2300 12.2700 12.0500 12.2600 432,700
12.0700 12.2000 11.9700 12.1600 979,100
Weekend
Weekend
12.2600 12.3900 12.0800 12.1300 2,753,900
12.2800 12.5400 12.2800 12.3100 647,100
12.3200 12.4300 12.1400 12.3100 660,000
12.5400 12.5400 12.3300 12.3700 650,900
12.3100 12.6100 12.3100 12.5100 729,800
Weekend
Weekend
12.5700 12.6200 12.3300 12.3400 750,500
12.1800 12.6300 12.1200 12.5000 1,772,300
12.3600 12.3600 12.1500 12.2500 994,100
12.0000 12.3000 12.0000 12.2600 839,100
12.0800 12.1100 11.9700 12.0000 4,400,500
Weekend
Weekend
12.0400 12.1900 11.9400 12.0800 1,034,200
12.1900 12.1900 11.8800 12.0200 845,900
12.0000 12.2500 11.9400 12.1700 1,071,900
12.4600 12.5700 12.0100 12.0700 1,702,000
12.3700 12.5700 12.2500 12.5200 683,800
Weekend
Weekend
12.0000 12.6600 11.8600 12.3700 1,472,300
3 · 6-K Pre-market · 07:30 ET FORM 6-K ↗ 2 · 6-K Pre-market · 07:01 ET 6-K ↗
12.2500 12.3300 11.9500 12.0500 1,627,800
12.1500 12.4900 12.0800 12.2700 1,248,400
1 · 6-K Next filing day · accepted 29 Jul, 19:10 ET FORM 6-K ↗
12.2000 12.3300 12.0200 12.1400 1,226,300
12.2900 12.3100 11.9800 12.2000 1,377,600
Weekend
Weekend
12.2900 12.3100 12.1500 12.2700 1,012,700
12.6800 12.6800 12.2800 12.3200 1,032,900
12.4400 12.7000 12.3500 12.5900 885,400
12.0800 12.2900 11.9900 12.2900 676,500

Announcement Events

Each title opens the filing on the SEC website. Registered users can summarise the filing and up to seven relevant exhibits linked within the same SEC submission.