TransAlta Corporation TAC
Open calendar →TransAlta Corporation Ordinary Shares · Company · NYSE
USD closing-price chart (daily close from yfinance · Last year)
USD 12.29 → 14.04 · 14.2%
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.
Date
Open
High
Low
Close
Volume
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
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