Ameren Illinois Co (AILLI) stock
AILLIOTCElectric & Other Services CombinedFiscal year ends December 31Also trades as AILIH, AILIM, AILIN, AILIO, AILIP, AILLM, AILLN, AILLO, AILLP
Last filing: 10-Q on Aug 3, 2026
$79.51+0.00 (0.00%)
Close on Oct 19, 2026Market cap –P/E –Yield –
Price history
Ameren Illinois share prices for every month, newest first. Adjusted for stock splits, not for dividends.
Close, Oct 19, 2026
$79.51
0.00% on the day
52-week range
$79.51 – $92.00
-13.6% from the high
Change over 52 weeks
-7.5%
From $86.00 on Oct 17, 2025
Average volume
15
Shares a day, last 90 sessions
| Month | Open | High | Low | Close | Change | Volume |
|---|---|---|---|---|---|---|
| Oct 2026 | $81.00 | $81.00 | $79.51 | $79.51 | -1.84% | 100 |
| Sep 2026 | $81.00 | $81.00 | $81.00 | $81.00 | 0.00% | 244 |
| Aug 2026 | $84.00 | $84.00 | $81.00 | $81.00 | -3.57% | 245 |
| Jul 2026 | $83.40 | $84.00 | $83.40 | $84.00 | +0.72% | 100 |
| Jun 2026 | $83.50 | $83.50 | $82.80 | $83.40 | -0.12% | 1,270 |
| May 2026 | $83.50 | $86.00 | $83.50 | $83.50 | 0.00% | 850 |
| Apr 2026 | $87.00 | $87.00 | $83.50 | $83.50 | -4.02% | 670 |
| Mar 2026 | $87.00 | $87.00 | $87.00 | $87.00 | 0.00% | 0 |
| Feb 2026 | $87.00 | $87.00 | $86.00 | $87.00 | 0.00% | 421 |
| Jan 2026 | $92.00 | $92.00 | $84.00 | $87.00 | -5.43% | 245 |
| Dec 2025 | $84.00 | $92.00 | $84.00 | $92.00 | +9.52% | 300 |
| Nov 2025 | $84.00 | $84.00 | $84.00 | $84.00 | 0.00% | 0 |
| Oct 2025 | $84.00 | $86.00 | $84.00 | $84.00 | -2.04% | 933 |
| Sep 2025 | $84.25 | $85.86 | $84.25 | $85.75 | +1.78% | 245 |
| Aug 2025 | $83.27 | $84.25 | $83.27 | $84.25 | +1.18% | 280 |
| Jul 2025 | $85.80 | $85.80 | $83.27 | $83.27 | -2.95% | 308 |
| Jun 2025 | $85.00 | $85.80 | $85.00 | $85.80 | +0.94% | 470 |
| May 2025 | $86.00 | $86.00 | $85.00 | $85.00 | -1.16% | 695 |
| Apr 2025 | $86.00 | $86.00 | $86.00 | $86.00 | 0.00% | 130 |
| Mar 2025 | $86.00 | $86.00 | $86.00 | $86.00 | 0.00% | 250 |
| Feb 2025 | $87.00 | $87.00 | $84.90 | $86.00 | -1.15% | 760 |
| Jan 2025 | $86.00 | $87.00 | $86.00 | $87.00 | +1.16% | 200 |
| Dec 2024 | $89.00 | $89.00 | $86.00 | $86.00 | -3.37% | 515 |
| Nov 2024 | $86.71 | $89.00 | $86.71 | $89.00 | +2.64% | 342 |
| Oct 2024 | $89.00 | $89.50 | $86.71 | $86.71 | -0.33% | 1,473 |
| Sep 2024 | $83.00 | $91.25 | $83.00 | $87.00 | +4.82% | 1,187 |
| Aug 2024 | $83.00 | $83.00 | $83.00 | $83.00 | 0.00% | 160 |
| Jul 2024 | $83.00 | $83.00 | $83.00 | $83.00 | 0.00% | 0 |
| Jun 2024 | $84.00 | $84.00 | $82.97 | $83.00 | -1.19% | 414 |
| May 2024 | $82.55 | $85.00 | $80.21 | $84.00 | +1.20% | 4,922 |
| Apr 2024 | $84.50 | $84.50 | $82.75 | $83.00 | -1.78% | 1,955 |
| Mar 2024 | $84.00 | $84.50 | $84.00 | $84.50 | +0.60% | 180 |
| Feb 2024 | $84.50 | $88.00 | $84.00 | $84.00 | -0.59% | 489 |
| Jan 2024 | $84.50 | $84.50 | $84.50 | $84.50 | 0.00% | 0 |
| Dec 2023 | $91.00 | $91.00 | $84.50 | $84.50 | -7.14% | 776 |
| Nov 2023 | $90.00 | $91.00 | $90.00 | $91.00 | +1.11% | 200 |
| Oct 2023 | $95.00 | $95.00 | $90.00 | $90.00 | -5.26% | 230 |
| Sep 2023 | $95.00 | $95.00 | $95.00 | $95.00 | 0.00% | 0 |
| Aug 2023 | $95.00 | $95.00 | $95.00 | $95.00 | 0.00% | 0 |
| Jul 2023 | $96.00 | $96.00 | $95.00 | $95.00 | -1.04% | 100 |
| Jun 2023 | $96.00 | $96.00 | $96.00 | $96.00 | 0.00% | 0 |
| May 2023 | $96.00 | $96.00 | $96.00 | $96.00 | 0.00% | 0 |
| Apr 2023 | $96.00 | $96.00 | $96.00 | $96.00 | 0.00% | 0 |
| Mar 2023 | $96.00 | $96.00 | $96.00 | $96.00 | 0.00% | 100 |
| Feb 2023 | $97.00 | $97.00 | $95.00 | $96.00 | -1.03% | 1,600 |
| Jan 2023 | $100.00 | $100.00 | $95.00 | $97.00 | -3.00% | 450 |
| Dec 2022 | $104.95 | $104.95 | $95.00 | $100.00 | -4.72% | 273 |
| Nov 2022 | $105.00 | $105.00 | $100.00 | $104.95 | -0.05% | 200 |
| Oct 2022 | $100.00 | $105.00 | $99.01 | $105.00 | +4.79% | 1,110 |
| Sep 2022 | $102.75 | $103.00 | $100.20 | $100.20 | -2.48% | 400 |
| Aug 2022 | $90.01 | $103.07 | $90.01 | $102.75 | +14.15% | 394 |
| Jul 2022 | $102.99 | $102.99 | $90.01 | $90.01 | -12.60% | 200 |
| Jun 2022 | $102.99 | $102.99 | $102.99 | $102.99 | 0.00% | 0 |
| May 2022 | $102.99 | $102.99 | $102.99 | $102.99 | 0.00% | 0 |
| Apr 2022 | $102.99 | $102.99 | $102.99 | $102.99 | 0.00% | 0 |
| Mar 2022 | $103.50 | $103.50 | $102.99 | $102.99 | -0.49% | 100 |
| Feb 2022 | $102.00 | $103.50 | $102.00 | $103.50 | +1.47% | 250 |
| Jan 2022 | $104.00 | $104.00 | $102.00 | $102.00 | -1.92% | 110 |
| Dec 2021 | $104.00 | $104.00 | $104.00 | $104.00 | 0.00% | 0 |
| Nov 2021 | $104.50 | $104.50 | $104.00 | $104.00 | -0.48% | 100 |
| Oct 2021 | $104.50 | $104.50 | $104.50 | $104.50 | +0.92% | 100 |
| Sep 2021 | $105.00 | $106.50 | $103.55 | $103.55 | -1.38% | 3,922 |
| Aug 2021 | $105.00 | $105.00 | $105.00 | $105.00 | 0.00% | 0 |
| Jul 2021 | $104.99 | $105.00 | $104.99 | $105.00 | +0.48% | 225 |
| Jun 2021 | $104.50 | $104.50 | $104.50 | $104.50 | 0.00% | 0 |
| May 2021 | $108.00 | $108.00 | $104.50 | $104.50 | -3.24% | 534 |
| Apr 2021 | $106.65 | $108.00 | $106.65 | $108.00 | +3.85% | 589 |
| Mar 2021 | $104.00 | $104.00 | $104.00 | $104.00 | 0.00% | 1,033 |
| Feb 2021 | $102.50 | $104.00 | $102.50 | $104.00 | +1.46% | 400 |
| Jan 2021 | $110.00 | $110.00 | $101.00 | $102.50 | -6.82% | 201 |
| Dec 2020 | $110.00 | $110.00 | $110.00 | $110.00 | 0.00% | 0 |
| Nov 2020 | $110.00 | $110.00 | $110.00 | $110.00 | 0.00% | 0 |
| Oct 2020 | $102.80 | $110.00 | $102.80 | $110.00 | +7.00% | 203 |
| Sep 2020 | $102.80 | $102.80 | $102.80 | $102.80 | 0.00% | 0 |
| Aug 2020 | $102.80 | $102.80 | $102.80 | $102.80 | 0.00% | 0 |
| Jul 2020 | $102.80 | $102.80 | $102.80 | $102.80 | 0.00% | 0 |
| Jun 2020 | $102.80 | $102.80 | $102.80 | $102.80 | 0.00% | 0 |
| May 2020 | $102.00 | $102.80 | $102.00 | $102.80 | +0.78% | 524 |
| Apr 2020 | $100.00 | $103.00 | $100.00 | $102.00 | -2.63% | 831 |
| Mar 2020 | $99.02 | $104.75 | $99.02 | $104.75 | +5.79% | 100 |
| Feb 2020 | $99.02 | $99.02 | $99.02 | $99.02 | 0.00% | 0 |
| Jan 2020 | $99.02 | $99.02 | $99.02 | $99.02 | 0.00% | 0 |
| Dec 2019 | $99.02 | $99.02 | $99.02 | $99.02 | 0.00% | 0 |
| Nov 2019 | $99.02 | $99.02 | $99.02 | $99.02 | 0.00% | 0 |
| Oct 2019 | $99.02 | $99.02 | $99.02 | $99.02 | 0.00% | 0 |
| Sep 2019 | $99.02 | $99.02 | $99.02 | $99.02 | 0.00% | 0 |
| Aug 2019 | $99.02 | $99.02 | $99.02 | $99.02 | 0.00% | 0 |
| Jul 2019 | $98.55 | $141.96 | $98.55 | $99.02 | +0.48% | 200 |
| Jun 2019 | $98.55 | $98.55 | $98.55 | $98.55 | 0.00% | 0 |
| May 2019 | $98.55 | $98.55 | $98.55 | $98.55 | 0.00% | 0 |
| Apr 2019 | $98.55 | $98.55 | $98.55 | $98.55 | 0.00% | 0 |
| Mar 2019 | $98.55 | $98.55 | $98.55 | $98.55 | 0.00% | 0 |
| Feb 2019 | $102.25 | $102.25 | $98.55 | $98.55 | -3.62% | 100 |
| Jan 2019 | $102.25 | $102.25 | $102.25 | $102.25 | 0.00% | 0 |
| Dec 2018 | $101.80 | $102.25 | $101.75 | $102.25 | +0.49% | 4,257 |
| Nov 2018 | $101.50 | $101.75 | $101.50 | $101.75 | +0.25% | 2,200 |
| Oct 2018 | $102.00 | $102.00 | $100.75 | $101.50 | -0.49% | 240 |
| Sep 2018 | $101.95 | $102.00 | $101.00 | $102.00 | +0.05% | 200 |
| Aug 2018 | $101.00 | $101.95 | $100.70 | $101.95 | +0.94% | 400 |
| Jul 2018 | $101.00 | $101.00 | $101.00 | $101.00 | 0.00% | 0 |
| Jun 2018 | $101.00 | $101.00 | $101.00 | $101.00 | 0.00% | 0 |
| May 2018 | $101.00 | $101.00 | $100.01 | $101.00 | -0.00% | 2,200 |
| Apr 2018 | $101.00 | $101.00 | $101.00 | $101.00 | 0.00% | 0 |
| Mar 2018 | $101.00 | $101.00 | $101.00 | $101.00 | 0.00% | 0 |
| Feb 2018 | $102.00 | $102.00 | $101.00 | $101.00 | -0.98% | 120 |
| Jan 2018 | $102.00 | $103.30 | $101.00 | $102.00 | 0.00% | 500 |
| Dec 2017 | $100.00 | $102.00 | $100.00 | $102.00 | +2.00% | 390 |
| Nov 2017 | $100.00 | $100.00 | $100.00 | $100.00 | 0.00% | 0 |
| Oct 2017 | $100.00 | $125.00 | $99.00 | $100.00 | 0.00% | 375 |
| Sep 2017 | $100.00 | $100.00 | $100.00 | $100.00 | 0.00% | 0 |
| Aug 2017 | $100.00 | $100.00 | $100.00 | $100.00 | 0.00% | 0 |
| Jul 2017 | $105.00 | $105.00 | $100.00 | $100.00 | -4.76% | 100 |
| Jun 2017 | $103.00 | $105.00 | $103.00 | $105.00 | +1.94% | 100 |
| May 2017 | $103.00 | $103.00 | $103.00 | $103.00 | 0.00% | 0 |
| Apr 2017 | $103.00 | $103.00 | $103.00 | $103.00 | 0.00% | 0 |
| Mar 2017 | $103.00 | $103.00 | $103.00 | $103.00 | 0.00% | 0 |
| Feb 2017 | $103.00 | $103.00 | $103.00 | $103.00 | 0.00% | 0 |
| Jan 2017 | $103.00 | $103.00 | $103.00 | $103.00 | 0.00% | 0 |
| Dec 2016 | $103.00 | $103.00 | $103.00 | $103.00 | 0.00% | 0 |
| Nov 2016 | $103.00 | $103.00 | $103.00 | $103.00 | 0.00% | 0 |
| Oct 2016 | $102.00 | $103.00 | $99.01 | $103.00 | +0.98% | 1,217 |
| Sep 2016 | $100.00 | $102.00 | $100.00 | $102.00 | +2.00% | 2,030 |
| Aug 2016 | $100.00 | $100.00 | $100.00 | $100.00 | 0.00% | 0 |
| Jul 2016 | $100.00 | $100.00 | $100.00 | $100.00 | 0.00% | 0 |
| Jun 2016 | $100.00 | $100.00 | $100.00 | $100.00 | 0.00% | 0 |
| May 2016 | $100.00 | $100.00 | $100.00 | $100.00 | 0.00% | 0 |
| Apr 2016 | $100.00 | $100.00 | $100.00 | $100.00 | 0.00% | 0 |
| Mar 2016 | $100.00 | $100.00 | $100.00 | $100.00 | 0.00% | 0 |
| Feb 2016 | $100.00 | $100.00 | $98.00 | $100.00 | 0.00% | 524 |
| Jan 2016 | $100.00 | $100.00 | $100.00 | $100.00 | 0.00% | 0 |
| Dec 2015 | $99.50 | $100.00 | $98.00 | $100.00 | +0.50% | 225 |
| Nov 2015 | $100.00 | $100.00 | $95.50 | $99.50 | -0.50% | 556 |
| Oct 2015 | $100.00 | $100.00 | $100.00 | $100.00 | 0.00% | 0 |
| Sep 2015 | $100.00 | $100.00 | $97.25 | $100.00 | 0.00% | 10,400 |
| Aug 2015 | $97.10 | $100.00 | $97.10 | $100.00 | +2.99% | 430 |
| Jul 2015 | $101.00 | $103.00 | $97.10 | $97.10 | -3.86% | 500 |
| Jun 2015 | $100.00 | $101.00 | $98.25 | $101.00 | +2.02% | 1,012 |
| May 2015 | $101.00 | $101.00 | $98.25 | $99.00 | -1.98% | 816 |
| Apr 2015 | $97.05 | $101.00 | $97.00 | $101.00 | +4.07% | 700 |
| Mar 2015 | $97.05 | $97.05 | $97.05 | $97.05 | 0.00% | 0 |
| Feb 2015 | $96.21 | $98.50 | $96.21 | $97.05 | +0.87% | 570 |
| Jan 2015 | $96.21 | $96.21 | $96.21 | $96.21 | 0.00% | 0 |
| Dec 2014 | $100.00 | $100.00 | $96.21 | $96.21 | -3.79% | 100 |
| Nov 2014 | $100.00 | $100.00 | $100.00 | $100.00 | 0.00% | 0 |
| Oct 2014 | $97.00 | $100.00 | $97.00 | $100.00 | +3.09% | 217 |
| Sep 2014 | $96.00 | $99.00 | $96.00 | $97.00 | +1.04% | 347 |
| Aug 2014 | $93.45 | $96.00 | $93.45 | $96.00 | +2.73% | 545 |
| Jul 2014 | $91.00 | $93.45 | $91.00 | $93.45 | +2.69% | 180 |
| Jun 2014 | $91.00 | $91.00 | $91.00 | $91.00 | 0.00% | 100 |
| May 2014 | $99.60 | $99.60 | $91.00 | $91.00 | -8.63% | 265 |
| Apr 2014 | $99.60 | $99.60 | $99.60 | $99.60 | 0.00% | 0 |
| Mar 2014 | $99.00 | $100.00 | $98.87 | $99.60 | +0.61% | 478 |
| Feb 2014 | $99.00 | $99.00 | $99.00 | $99.00 | 0.00% | 0 |
| Jan 2014 | $96.15 | $99.00 | $96.15 | $99.00 | +2.96% | 200 |
| Dec 2013 | $97.50 | $97.50 | $96.15 | $96.15 | -1.38% | 124 |
| Nov 2013 | $97.50 | $97.50 | $97.50 | $97.50 | 0.00% | 0 |
| Oct 2013 | $97.50 | $97.50 | $97.50 | $97.50 | 0.00% | 0 |
| Sep 2013 | $96.00 | $97.50 | $96.00 | $97.50 | +1.56% | 390 |
| Aug 2013 | $100.00 | $100.00 | $96.00 | $96.00 | -2.59% | 500 |
| Jul 2013 | $98.55 | $98.55 | $98.55 | $98.55 | 0.00% | 0 |
| Jun 2013 | $102.00 | $102.00 | $98.55 | $98.55 | -3.38% | 349 |
| May 2013 | $99.15 | $102.00 | $99.15 | $102.00 | +2.87% | 8,614 |
| Apr 2013 | $101.00 | $101.75 | $99.15 | $99.15 | -1.83% | 514 |
| Mar 2013 | $100.00 | $101.00 | $100.00 | $101.00 | +1.00% | 200 |
| Feb 2013 | $99.15 | $100.00 | $99.15 | $100.00 | +0.86% | 100 |
| Jan 2013 | $101.50 | $101.50 | $99.15 | $99.15 | -2.32% | 1,614 |
| Dec 2012 | $101.50 | $101.50 | $101.50 | $101.50 | 0.00% | 0 |
| Nov 2012 | $101.50 | $101.50 | $101.50 | $101.50 | 0.00% | 0 |
| Oct 2012 | $100.75 | $101.50 | $100.75 | $101.50 | -1.46% | 7,000 |
| Sep 2012 | $103.00 | $103.00 | $103.00 | $103.00 | 0.00% | 0 |
| Aug 2012 | $100.75 | $103.00 | $97.75 | $103.00 | +7.01% | 852 |
| Jul 2012 | $99.50 | $101.00 | $96.25 | $96.25 | -3.27% | 1,656 |
| Jun 2012 | $95.15 | $100.50 | $95.15 | $99.50 | +4.57% | 9,209 |
| May 2012 | $98.50 | $98.50 | $94.05 | $95.15 | -3.40% | 319 |
| Apr 2012 | $99.00 | $100.00 | $98.50 | $98.50 | -0.51% | 671 |
| Mar 2012 | $97.50 | $99.00 | $97.50 | $99.00 | +1.54% | 9,014 |
| Feb 2012 | $99.25 | $99.25 | $97.50 | $97.50 | -1.76% | 204 |
| Jan 2012 | $99.25 | $99.25 | $99.25 | $99.25 | 0.00% | 0 |
| Dec 2011 | $98.25 | $99.25 | $97.25 | $99.25 | +1.02% | 6,303 |
| Nov 2011 | $95.00 | $103.13 | $94.25 | $98.25 | +5.65% | 11,914 |
| Oct 2011 | $93.00 | $93.25 | $91.75 | $93.00 | 0.00% | 11,614 |
| Sep 2011 | $103.00 | $103.00 | $93.00 | $93.00 | -9.71% | 244 |
| Aug 2011 | $91.75 | $103.00 | $91.75 | $103.00 | +12.26% | 400 |
| Jul 2011 | $90.25 | $91.75 | $90.25 | $91.75 | +0.82% | 5,814 |
| Jun 2011 | $90.00 | $91.00 | $90.00 | $91.00 | +1.11% | 400 |
| May 2011 | $89.00 | $90.00 | $85.00 | $90.00 | +1.12% | 1,196 |
| Apr 2011 | $89.00 | $89.00 | $89.00 | $89.00 | 0.00% | 0 |
| Mar 2011 | $88.00 | $89.00 | $88.00 | $89.00 | +1.14% | 120 |
| Feb 2011 | $89.00 | $89.00 | $88.00 | $88.00 | -1.12% | 120 |
| Jan 2011 | $87.00 | $89.50 | $86.50 | $89.00 | +2.30% | 560 |
| Dec 2010 | $87.50 | $88.00 | $86.50 | $87.00 | -0.57% | 960 |
| Nov 2010 | $90.00 | $90.00 | $86.25 | $87.50 | -2.78% | 400 |
| Oct 2010 | $75.00 | $90.00 | $75.00 | $90.00 | +20.00% | 2,706 |
| Sep 2010 | $72.10 | $75.00 | $72.10 | $75.00 | +4.02% | 160 |
| Aug 2010 | $72.10 | $72.10 | $72.10 | $72.10 | 0.00% | 0 |
| Jul 2010 | $72.10 | $72.10 | $72.10 | $72.10 | 0.00% | 0 |
| Jun 2010 | $77.00 | $77.00 | $72.10 | $72.10 | – | 150 |
Seasonality
AILLI return in each calendar month over the last 10 years, including dividends. The current month runs to the latest close.
| Year | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Average | -0.3% | -0.4% | 0.6% | 0.9% | -0.2% | 0.2% | -0.7% | 1.3% | 0.3% | 1.6% | 0.4% | -0.4% |
| Months up | 6 of 10 | 2 of 10 | 2 of 10 | 7 of 10 | 2 of 10 | 2 of 10 | 7 of 10 | 3 of 10 | 3 of 10 | 7 of 10 | 3 of 9 | 3 of 9 |
| 2026 | -4.1% | 0.0% | 0.0% | -2.6% | 0.0% | -0.1% | 2.3% | -3.6% | 0.0% | -0.3% | ||
| 2025 | 2.7% | -1.1% | 0.0% | 1.5% | -1.2% | 0.9% | -1.5% | 1.2% | 1.8% | -0.5% | 0.0% | 9.5% |
| 2024 | 1.6% | -0.6% | 0.6% | -0.2% | 1.2% | -1.2% | 1.6% | 0.0% | 4.8% | 1.1% | 2.6% | -3.4% |
| 2023 | -1.7% | -1.0% | 0.0% | 1.4% | 0.0% | 0.0% | 0.3% | 0.0% | 0.0% | -4.0% | 1.1% | -7.1% |
| 2022 | -0.7% | 1.5% | -0.5% | 1.3% | 0.0% | 0.0% | -11.5% | 14.2% | -2.5% | 6.2% | -0.0% | -4.7% |
| 2021 | -5.7% | 1.5% | 0.0% | 5.1% | -3.2% | 0.0% | 1.7% | 0.0% | -1.4% | 2.2% | -0.5% | 0.0% |
| 2020 | 1.3% | 0.0% | 5.8% | -1.4% | 0.8% | 0.0% | 1.3% | 0.0% | 0.0% | 8.3% | 0.0% | 0.0% |
| 2019 | 1.3% | -3.6% | 0.0% | 1.3% | 0.0% | 0.0% | 1.4% | 0.0% | 0.0% | 1.3% | 0.0% | 0.0% |
| 2018 | 1.3% | -1.0% | 0.0% | 1.3% | -0.0% | 0.0% | 1.3% | 0.9% | 0.0% | 0.8% | 0.2% | 0.5% |
| 2017 | 1.3% | 0.0% | 0.0% | 1.3% | 0.0% | 1.9% | -3.6% | 0.0% | 0.0% | 1.3% | 0.0% | 2.0% |