Plug Power (STU:PLUN) Cyclically Adjusted PB Ratio: (As of Sep. 20, 2026)

Author: Vera Yuan Vera Yuan
Vera Yuan
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Director of Data and Quant Analytics at GuruFocus
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Charlie Tian
Charlie Tian
Founder & CEO of GuruFocus
Dr. Charlie Tian is the founder and CEO of GuruFocus.com, a leading global investment research platform established in 2004. With a Ph.D. in physics, Dr. Tian transitioned from science to finance, applying a data-driven, disciplined approach to value investing.

STU:PLUN Plug Power Inc STU:PLUN
37 GF Score
Price €1.82
GF Value €1.24
Valuation Significantly Overvalued
! 5 Warning Signs
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What is Plug Power Cyclically Adjusted PB Ratio?

Shiller PE for Stocks: The True Measure of Stock Valuation


Plug Power  (STU:PLUN) Cyclically Adjusted PB Ratio Explanation

Compared with the regular PB Ratio, which works poorly for cyclical businesses, the Cyclically Adjusted PB Ratio smoothed out the fluctuations of book value during business cycles. Therefore it is more accurate in reflecting the valuation of the company.

If a company has consistent business performance, the Cyclically Adjusted PB Ratio should give similar results to regular PB Ratio.


Plug Power Cyclically Adjusted PB Ratio Related Terms


Plug Power Cyclically Adjusted PB Ratio Historical Data

* Premium members only.

The historical data trend for Plug Power's Cyclically Adjusted PB Ratio 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.

Plug Power Cyclically Adjusted PB Ratio Chart

Plug Power Annual Data
Trend Dec16 Dec17 Dec18 Dec19 Dec20 Dec21 Dec22 Dec23 Dec24 Dec25
Cyclically Adjusted PB Ratio
Get a 7-Day Free Trial Premium Member Only Premium Member Only 19.01 5.76 1.70 0.86 0.62

Plug Power Quarterly Data
Sep21 Dec21 Mar22 Jun22 Sep22 Dec22 Mar23 Jun23 Sep23 Dec23 Mar24 Jun24 Sep24 Dec24 Mar25 Jun25 Sep25 Dec25 Mar26 Jun26
Cyclically Adjusted PB Ratio 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 0.43 0.68 0.58 0.66 0.78

STU:PLUN vs HAYW, ATKR, PLPC: Cyclically Adjusted PB Ratio Comparison

For the Electrical Equipment & Parts subindustry, Plug Power'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.


Plug Power Cyclically Adjusted PB Ratio vs Industrial Products Industry

For the Industrial Products industry and Industrials sector, Plug Power's Cyclically Adjusted PB Ratio distribution charts can be found below:

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


STU:PLUN
37GF Score
Plug Power Inc STU:PLUN
Cyclically Adjusted PB Ratio is just one metric. See GF Score™, valuation, warning signs, and more.
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Plug Power Cyclically Adjusted PB Ratio Calculation

Like the Shiller PE Ratio, the Cyclically Adjusted PB Ratio takes the Book Value per Share from the past 10 years, adjusts it for inflation, and then calculates the average. This average is then used for the P/B calculation. Because it considers this 10-year average, it's often referred to as the CAPB Ratio.

The Shiller PE Ratio was first used by professor Robert Shiller to measure the valuation of the overall market. The similar calculation is applied by GuruFocus to calculate the Cyclically Adjusted PB Ratio.

Plug Power's Cyclically Adjusted Book per Share for the quarter that ended in Jun. 2026 is calculated as:

For example, Plug Power'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)
=0.368/333.9520*333.9520
=0.368

Current CPI (Jun. 2026) = 333.9520.

Plug Power Quarterly Data

Book Value per Share CPI Adj_Book
201609 0.462 241.428 0.639
201612 0.422 241.432 0.584
201703 0.297 243.801 0.407
201706 0.383 244.955 0.522
201709 0.323 246.819 0.437
201712 0.268 246.524 0.363
201803 0.188 249.554 0.252
201806 0.104 251.989 0.138
201809 0.057 252.439 0.075
201812 0.011 251.233 0.015
201903 -0.005 254.202 -0.007
201906 -0.040 256.143 -0.052
201909 -0.055 256.759 -0.072
201912 0.381 256.974 0.495
202003 0.324 258.115 0.419
202006 0.642 257.797 0.832
202009 1.349 260.280 1.731
202012 2.617 260.474 3.355
202103 7.390 264.877 9.317
202106 7.135 271.696 8.770
202109 7.050 274.310 8.583
202112 7.011 278.802 8.398
202203 6.960 287.504 8.084
202206 7.174 296.311 8.085
202209 7.424 296.808 8.353
202212 6.444 296.797 7.251
202303 6.080 301.836 6.727
202306 5.695 305.109 6.233
202309 5.475 307.789 5.940
202312 4.328 306.746 4.712
202403 3.951 312.332 4.224
202406 3.540 314.175 3.763
202409 3.083 315.301 3.265
202412 1.910 315.605 2.021
202503 1.831 319.799 1.912
202506 1.310 322.561 1.356
202509 1.062 324.800 1.092
202512 0.613 324.054 0.632
202603 0.482 330.213 0.487
202606 0.368 333.952 0.368

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

Is Plug Power (STU:PLUN) Overvalued in 2026?

Based on GuruFocus' analysis, Plug Power stock appears to be overvalued. The current stock price of €1.82 is trading 46.7% above its estimated GF Value™ of €1.24. GuruFocus considers Plug Power to be Significantly Overvalued.

Key valuation signals for STU:PLUN:

  • Cyclically Adjusted PB Ratio:
  • GF Value™: €1.24 vs. price of €1.82 (46.7% above fair value)
  • GF Score™: 37/100 with 5 warning signs

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


Plug Power Business Description

Address 125 Vista Boulevard, Slingerlands, NY, USA, 12159
Plug Power Inc is building an end-to-end green hydrogen ecosystem, from production, storage, and delivery to energy generation. The company plans to build and operate green hydrogen highways across North America and Europe. Plug will deliver its green hydrogen solutions directly to its customers and through joint venture partners into multiple end markets, including material handling, e-mobility, power generation, and industrial applications.
37GF Score

Get the complete analysis for STU:PLUN

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

€1.82
Price
€1.24
GF Value