AltaGas (STU:AQ3) Cyclically Adjusted Book per Share: €16.75 (As of Jun. 2026)

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STU:AQ3 AltaGas Ltd STU:AQ3
70 GF Score
Price €34.40
GF Value €22.44
Valuation Significantly Overvalued
! 13 Warning Signs
View Full Analysis

What is AltaGas Cyclically Adjusted Book per Share?

AltaGas STU:AQ3 +0.58% 70 Cyclically Adjusted Book per Share is €16.75 as of Jun. 2026. GuruFocus rates STU:AQ3 with a GF Score™ of 70/100 and a GF Value™ of €22.44 (Significantly Overvalued). The stock has 13 warning signs investors should review.

E10 is a concept invented by Prof. Robert Shiller, who uses E10 for his Shiller PE Ratio calculation. E10 is the average of the inflation adjusted earnings of a company over the past 10 years. The similar calculation is applied by GuruFocus to calculate the Cyclically Adjusted Book per Share and the Cyclically Adjusted PB Ratio. The Cyclically Adjusted Book per Share is the average of the inflation adjusted Book Value per Share of a company over the past 10 years.

AltaGas's adjusted book value per share for the three months ended in Jun. 2026 was €18.508. Add all the adjusted book value per share for the past 10 years together and divide the count will get our Cyclically Adjusted Book per Share, which is €16.75 for the trailing ten years ended in Jun. 2026.

During the past 12 months, AltaGas's average Cyclically Adjusted Book Growth Rate was -100.00% per year. During the past 3 years, the average Cyclically Adjusted Book Growth Rate was 3.30% per year. During the past 5 years, the average Cyclically Adjusted Book Growth Rate was 5.40% per year. During the past 10 years, the average Cyclically Adjusted Book Growth Rate was 6.00% per year. Please click Growth Rate Calculation Example (GuruFocus) to see how GuruFocus calculates Wal-Mart Stores Inc (WMT)'s revenue growth rate. You can apply the same method to get the Cyclically Adjusted Book Growth Rate using Cyclically Adjusted Book per Share data.

During the past 13 years, the highest 3-Year average Cyclically Adjusted Book Growth Rate of AltaGas was 8.80% per year. The lowest was 3.30% per year. And the median was 7.30% per year.

As of today (2026-08-02), AltaGas's current stock price is €34.40. AltaGas's Cyclically Adjusted Book per Share for the quarter that ended in Jun. 2026 was €16.75. AltaGas's Cyclically Adjusted PB Ratio of today is 2.05.

During the past 13 years, the highest Cyclically Adjusted PB Ratio of AltaGas was 2.19. The lowest was 0.60. And the median was 1.21.


AltaGas  (STU:AQ3) Cyclically Adjusted Book per Share Explanation

If a company grows much fast than inflation, Cyclically Adjusted Book per Share may underestimate the company's equity. Cyclically Adjusted PB Ratio can seem to be too high even the actual PB Ratio is low.

For the Cyclically Adjusted PB Ratio, the book value of the past 10 years are inflation-adjusted and averaged. The result is used for P/B calculation. Since it looks at the average over the last 10 years, the Cyclically Adjusted PB Ratio is also called CAPB Ratio.

The Shiller PE Ratio was first used by professor Robert Shiller. He uses E10 for his Shiller PE Ratio calculation. E10 is the average of the inflation adjusted earnings per share of a company over the past 10 years. The similar calculation is applied by GuruFocus to calculate the Cyclically Adjusted PB Ratio. The Cyclically Adjusted Book per Share is the average of the inflation adjusted book value per share of a company over the past 10 years.

AltaGas's Cyclically Adjusted PB Ratio of today is calculated as

Cyclically Adjusted PB Ratio=Share Price/Cyclically Adjusted Book per Share
=34.40/16.75
=2.05

* For Operating Data section: All numbers are indicated by the unit behind each term and all currency related amount are in USD.
* For other sections: All numbers are in millions except for per share data, ratio, and percentage. All currency related amount are indicated in the company's associated stock exchange currency.

During the past 13 years, the highest Cyclically Adjusted PB Ratio of AltaGas was 2.19. The lowest was 0.60. And the median was 1.21.


Be Aware

Cyclically Adjusted PB Ratio works better for cyclical companies. It gives you a better idea on the company's real book value.


AltaGas Cyclically Adjusted Book per Share Related Terms


AltaGas Cyclically Adjusted Book per Share Historical Data

* Premium members only.

The historical data trend for AltaGas's Cyclically Adjusted Book per Share can be seen below:

* For Operating Data section: All numbers are indicated by the unit behind each term and all currency related amount are in USD.
* For other sections: All numbers are in millions except for per share data, ratio, and percentage. All currency related amount are indicated in the company's associated stock exchange currency.

AltaGas Cyclically Adjusted Book per Share Chart

AltaGas Annual Data
Trend Dec16 Dec17 Dec18 Dec19 Dec20 Dec21 Dec22 Dec23 Dec24 Dec25
Cyclically Adjusted Book per Share
Get a 7-Day Free Trial Premium Member Only Premium Member Only 15.08 16.62 16.88 16.96 16.30

AltaGas Quarterly Data
Sep21 Dec21 Mar22 Jun22 Sep22 Dec22 Mar23 Jun23 Sep23 Dec23 Mar24 Jun24 Sep24 Dec24 Mar25 Jun25 Sep25 Dec25 Mar26 Jun26
Cyclically Adjusted Book per Share Get a 7-Day Free Trial Premium Member Only Premium Member Only Premium Member Only Premium Member Only Premium Member Only Premium Member Only Premium Member Only Premium Member Only Premium Member Only Premium Member Only Premium Member Only Premium Member Only 16.14 15.90 16.30 16.59 16.75

STU:AQ3 vs WMB, EPD, KMI: Cyclically Adjusted Book per Share Comparison

For the Oil & Gas Midstream subindustry, AltaGas's Cyclically Adjusted PB Ratio, along with its competitors' market caps and Cyclically Adjusted PB Ratio data, can be viewed below:

* Competitive companies are chosen from companies within the same industry, with headquarter located in same country, with closest market capitalization; x-axis shows the market cap, and y-axis shows the term value; the bigger the dot, the larger the market cap. Note that "N/A" values will not show up in the chart.


AltaGas Cyclically Adjusted PB Ratio vs Oil & Gas Industry

For the Oil & Gas industry and Energy sector, AltaGas's Cyclically Adjusted PB Ratio distribution charts can be found below:

* The bar in red indicates where AltaGas's Cyclically Adjusted PB Ratio falls into.


STU:AQ3
70GF Score
AltaGas Ltd STU:AQ3
Cyclically Adjusted Book per Share is just one metric. See GF Score™, valuation, warning signs, and more.
View Full Analysis

AltaGas Cyclically Adjusted Book per Share Calculation

E10 is a concept invented by Prof. Robert Shiller, who uses E10 for his Shiller PE Ratio calculation. E10 is the average of the inflation adjusted earnings of a company over the past 10 years. The similar calculation is applied by GuruFocus to calculate the Cyclically Adjusted Book per Share and the Cyclically Adjusted PB Ratio. The Cyclically Adjusted Book per Share is the average of the inflation adjusted Book Value per Share of a company over the past 10 years.

What is Cyclically Adjusted Book per Share? How do we calculate Cyclically Adjusted Book per Share?

Cyclically Adjusted Book per Share is the average of the inflation adjusted Book Value per Share of a company over the past 10 years. Let's use an example to explain.

If we want to calculate the Cyclically Adjusted Book per Share of Wal-Mart (WMT) for Dec. 31, 2010, we need to have the inflation data and the book value per share from 2001 through 2010.

We adjusted the 2001 book value per share data with the total inflation from 2001 through 2010 to the equivalent book value in 2010. If the total inflation from 2001 to 2010 is 40%, and Wal-Mart's book value is $1 a share in 2001, then the 2001's equivalent book value in 2010 is $1.4 a share. If Wal-Mart's book value is $1 again in 2002, and the total inflation from 2002 through 2010 is 35%, then the equivalent 2002 book value in 2010 is $1.35. So on and so forth, you get the equivalent book value per share of past 10 years. Then you add them together and divided the sum by the count to get Cyclically Adjusted Book per Share.

Please note that we use the CPI data of the country/region where the company is headquartered. If the CPI data for that country/region is not available, then we will use the CPI data of the United States as default.

For example, AltaGas's adjusted Book Value per Share data for the three months ended in Jun. 2026 was:

Adj_Book= Book Value per Share /CPI of Jun. 2026 (Change)*Current CPI (Jun. 2026)
=18.508/133.5265*133.5265
=18.508

Current CPI (Jun. 2026) = 133.5265.

AltaGas Quarterly Data

Book Value per Share CPI Adj_Book
201609 14.525 101.765 19.058
201612 15.310 101.449 20.151
201703 14.719 102.634 19.149
201706 13.555 103.029 17.567
201709 13.160 103.345 17.003
201712 12.441 103.345 16.074
201803 11.947 105.004 15.192
201806 13.559 105.557 17.152
201809 12.721 105.636 16.080
201812 13.551 105.399 17.167
201903 15.152 106.979 18.912
201906 14.818 107.690 18.373
201909 15.343 107.611 19.038
201912 14.541 107.769 18.016
202003 16.244 107.927 20.097
202006 15.584 108.401 19.196
202009 14.614 108.164 18.041
202012 13.694 108.559 16.843
202103 14.616 110.298 17.694
202106 14.404 111.720 17.216
202109 14.716 112.905 17.404
202112 14.488 113.774 17.003
202203 15.429 117.646 17.512
202206 16.539 120.806 18.281
202209 18.837 120.648 20.848
202212 16.957 120.964 18.718
202303 17.526 122.702 19.072
202306 17.466 124.203 18.777
202309 17.565 125.230 18.729
202312 16.971 125.072 18.118
202403 18.100 126.258 19.142
202406 17.972 127.522 18.818
202409 17.047 127.285 17.883
202412 18.812 127.364 19.722
202503 18.763 129.181 19.394
202506 17.443 129.892 17.931
202509 17.112 130.287 17.537
202512 17.348 130.366 17.769
202603 18.120 132.262 18.293
202606 18.508 133.527 18.508

Add all the adjusted book value per share together and divide the count will get our Cyclically Adjusted Book per Share.

What does a Cyclically Adjusted Book per Share of €16.75 mean?
AltaGas (STU:AQ3) has a Cyclically Adjusted Book per Share of €16.75 as of Jun. 2026. Cyclically adjusted book value per share represents the company's inflation-adjusted book value per share over a 10-year period. View historical data on AltaGas and its competitors.
Is AltaGas' Cyclically Adjusted Book per Share too high?
AltaGas' current Cyclically Adjusted Book per Share is €16.75. Overall, AltaGas has a GF Score™ of 70/100 and is considered Significantly Overvalued, reflecting its overall financial health beyond just this single metric.
How does AltaGas' Cyclically Adjusted Book per Share compare to WMB and EPD?
AltaGas' Cyclically Adjusted Book per Share of €16.75 can be compared against companies in the Oil & Gas industry. See the competitive comparison table and distribution chart on this page for a detailed peer-by-peer breakdown.
What is a good Cyclically Adjusted Book per Share for an Oil & Gas company?
A good Cyclically Adjusted Book per Share depends on the Oil & Gas industry context. However, Cyclically Adjusted Book per Share should not be evaluated in isolation — investors should consider it alongside profitability, growth, and financial strength metrics. Use the industry distribution chart on this page to see where any company falls relative to its peers.
What does a high Cyclically Adjusted Book per Share mean?
A high Cyclically Adjusted Book per Share can signal that a stock is expensive relative to its fundamentals. Cyclically adjusted book value per share represents the company's inflation-adjusted book value per share over a 10-year period. View historical data on AltaGas and its competitors. AltaGas's current Cyclically Adjusted Book per Share is €16.75. However, context matters — high-growth companies often justify higher valuations. Always evaluate alongside other metrics like GF Score™ and GF Value™.
Is AltaGas stock overvalued right now?
Based on GuruFocus' analysis, AltaGas (STU:AQ3) is currently considered Significantly Overvalued. The stock's GF Value™ is €22.44, compared to a current price of €34.40 — trading 53.3% above its estimated fair value. The current Cyclically Adjusted Book per Share is €16.75. AltaGas' overall GF Score™ is 70/100 with 13 warning signs to review. Investors should evaluate multiple metrics — including profitability, growth, and financial strength — before making a decision.
How is Cyclically Adjusted Book per Share calculated?
Cyclically Adjusted Book per Share is calculated from a company's financial statements. For AltaGas (STU:AQ3), the current Cyclically Adjusted Book per Share is €16.75 as of Jun. 2026. GuruFocus calculates this using data sourced from SEC filings and annual reports. See the calculation section and 30-year financial data on this page for the full breakdown.

Is AltaGas (STU:AQ3) Overvalued in 2026?

Based on GuruFocus' analysis, AltaGas stock appears to be overvalued. The current stock price of €34.40 is trading 53.3% above its estimated GF Value™ of €22.44. GuruFocus considers AltaGas to be Significantly Overvalued.

Key valuation signals for STU:AQ3:

  • Cyclically Adjusted Book per Share: €16.75
  • GF Value™: €22.44 vs. price of €34.40 (53.3% above fair value)
  • GF Score™: 70/100 with 13 warning signs

No single metric tells the full story. See the STU:AQ3 stock analysis page for a complete view including 30-year financials, guru trades, and insider activity.


AltaGas Business Description

Industry EnergyOil & Gas
Address 707 - 5th Street SW, Suite 1300, Calgary, AB, CAN, T2P 1V8
AltaGas Ltd is a North American energy infrastructure company that connects customers and markets to energy sources. AltaGas has three reporting segments: Utilities, Midstream, and Corporate/Other. The majority of its revenue is generated from the Midstream segment, which operates a North American energy platform that moves natural gas and LPGs from the wellhead to markets. It exports propane and butane to Asia through its LPG terminals, and runs natural gas gathering, processing, fractionation, liquids handling, and storage infrastructure. The segment also includes its natural gas and natural gas liquids (NGLs) marketing business, domestic logistics, trucking and rail terminals, and liquid and natural gas storage capability. Geographically, the firm derives its key revenue from the U.S.
70GF Score

Get the complete analysis for STU:AQ3

Cyclically Adjusted Book per Share is just one metric. See GF Value™, 30-year financials, guru trades, warning signs, and more.

€34.40
Price
€22.44
GF Value