Amphastar Pharmaceuticals (STU:29A) Cyclically Adjusted PB Ratio: 1.69 (As of Aug. 16, 2026) — 52% Below Median

Author: Vera Yuan Vera Yuan
Vera Yuan
Vera Yuan
Director of Data and Quant Analytics at GuruFocus
Focused on building reliable datasets, financial models, and research tools for value-minded investors. Committed to turning complex data into practical guidance for value-investing and long-term wealth.
Reviewed by: Charlie Tian Charlie Tian
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:29A Amphastar Pharmaceuticals Inc STU:29A
79 GF Score
Price €18.04
GF Value €31.09
Valuation Significantly Undervalued
! 4 Warning Signs
View Full Analysis

What is Amphastar Pharmaceuticals Cyclically Adjusted PB Ratio?

Amphastar Pharmaceuticals STU:29A +3.50% 79 Cyclically Adjusted PB Ratio is 1.69 as of Aug. 16, 2026, which is 52% below its 10-year median of 3.50. GuruFocus rates STU:29A with a GF Score™ of 79/100 and a GF Value™ of €31.09 (Significantly Undervalued). The stock has 4 warning signs investors should review. Among 716 Drug Manufacturers companies, Amphastar Pharmaceuticals ranks better than 53.91% on this metric.

As of today (2026-08-16), Amphastar Pharmaceuticals's current share price is €18.04. Amphastar Pharmaceuticals's Cyclically Adjusted Book per Share for the quarter that ended in Jun. 2026 was €10.65. Amphastar Pharmaceuticals's Cyclically Adjusted PB Ratio for today is 1.69.

The historical rank and industry rank for Amphastar Pharmaceuticals's Cyclically Adjusted PB Ratio or its related term are showing as below:

STU:29A' s Cyclically Adjusted PB Ratio Range Over the Past 10 Years
Min: 1.41   Med: 3.5   Max: 6.79
Current: 1.71

During the past years, Amphastar Pharmaceuticals's highest Cyclically Adjusted PB Ratio was 6.79. The lowest was 1.41. And the median was 3.50.

STU:29A's Cyclically Adjusted PB Ratio is ranked better than
53.91% of 716 companies
in the Drug Manufacturers industry
Industry Median: 1.76 vs STU:29A: 1.71

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.

Amphastar Pharmaceuticals's adjusted book value per share data for the three months ended in Jun. 2026 was €15.677. 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 €10.65 for the trailing ten years ended in Jun. 2026.

Shiller PE for Stocks: The True Measure of Stock Valuation


Amphastar Pharmaceuticals  (STU:29A) 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.


Amphastar Pharmaceuticals Cyclically Adjusted PB Ratio Related Terms


Amphastar Pharmaceuticals Cyclically Adjusted PB Ratio Historical Data

* Premium members only.

The historical data trend for Amphastar Pharmaceuticals'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.

Amphastar Pharmaceuticals Cyclically Adjusted PB Ratio Chart

Amphastar Pharmaceuticals 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 0.00 3.16 6.50 3.56 2.33

Amphastar Pharmaceuticals 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 2.08 2.35 2.33 1.64 1.64

STU:29A vs ESPR, NIKA, BIOA: Cyclically Adjusted PB Ratio Comparison

For the Drug Manufacturers - Specialty & Generic subindustry, Amphastar Pharmaceuticals'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.


Amphastar Pharmaceuticals Cyclically Adjusted PB Ratio vs Drug Manufacturers Industry

For the Drug Manufacturers industry and Healthcare sector, Amphastar Pharmaceuticals's Cyclically Adjusted PB Ratio distribution charts can be found below:

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


STU:29A
79GF Score
Amphastar Pharmaceuticals Inc STU:29A
Cyclically Adjusted PB Ratio is just one metric. See GF Score™, valuation, warning signs, and more.
View Full Analysis

Amphastar Pharmaceuticals 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.

Amphastar Pharmaceuticals's Cyclically Adjusted PB Ratio for today is calculated as

Cyclically Adjusted PB Ratio=Share Price/ Cyclically Adjusted Book per Share
=18.04/10.65
=1.69

* 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.

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

For example, Amphastar Pharmaceuticals'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)
=15.677/333.9520*333.9520
=15.677

Current CPI (Jun. 2026) = 333.9520.

Amphastar Pharmaceuticals Quarterly Data

Book Value per Share CPI Adj_Book
201609 6.357 241.428 8.793
201612 6.749 241.432 9.335
201703 6.623 243.801 9.072
201706 6.414 244.955 8.744
201709 6.045 246.819 8.179
201712 6.049 246.524 8.194
201803 5.686 249.554 7.609
201806 5.911 251.989 7.834
201809 5.930 252.439 7.845
201812 6.266 251.233 8.329
201903 6.294 254.202 8.269
201906 7.269 256.143 9.477
201909 7.491 256.759 9.743
201912 7.369 256.974 9.576
202003 7.378 258.115 9.546
202006 7.435 257.797 9.631
202009 7.238 260.280 9.287
202012 6.963 260.474 8.927
202103 7.139 264.877 9.001
202106 7.299 271.696 8.971
202109 7.620 274.310 9.277
202112 8.263 278.802 9.898
202203 8.931 287.504 10.374
202206 9.641 296.311 10.866
202209 10.495 296.808 11.808
202212 10.373 296.797 11.672
202303 10.635 301.836 11.767
202306 11.140 305.109 12.193
202309 11.642 307.789 12.632
202312 12.198 306.746 13.280
202403 12.665 312.332 13.542
202406 13.535 314.175 14.387
202409 13.554 315.301 14.356
202412 14.687 315.605 15.541
202503 14.578 319.799 15.223
202506 14.126 322.561 14.625
202509 14.278 324.800 14.680
202512 14.758 324.054 15.209
202603 14.987 330.213 15.157
202606 15.677 333.952 15.677

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.

What does a Cyclically Adjusted PB Ratio of 1.69 mean?
Amphastar Pharmaceuticals (STU:29A) has a Cyclically Adjusted PB Ratio of 1.69 as of Aug. 16, 2026. Cyclically Adjusted PB Ratio is the ratio of share price to a company's inflation-adjusted book value per share over a 10-year period. View historical data on Amphastar Pharmaceuticals and its competitors. This is 52% below median its historical median of 3.50. Over the past decade, Amphastar Pharmaceuticals' Cyclically Adjusted PB Ratio has ranged from 1.41 to 6.79. According to the industry distribution chart, Amphastar Pharmaceuticals ranks #330 out of 716 companies in the Drug Manufacturers industry, placing it in the top 46.1%.
Is Amphastar Pharmaceuticals' Cyclically Adjusted PB Ratio too high?
Amphastar Pharmaceuticals' current Cyclically Adjusted PB Ratio of 1.69 is 52% below median its 10-year median of 3.50. Over the past 10 years, this metric has ranged from a low of 1.41 to a high of 6.79. The Drug Manufacturers industry median Cyclically Adjusted PB Ratio is 1.76. Amphastar Pharmaceuticals' value of 1.69 is 4% below this industry median. Based on the distribution chart, Amphastar Pharmaceuticals ranks #330 out of 716 companies in the Drug Manufacturers industry, which is above the industry midpoint. Overall, Amphastar Pharmaceuticals has a GF Score™ of 79/100 and is considered Significantly Undervalued, reflecting its overall financial health beyond just this single metric.
How does Amphastar Pharmaceuticals' Cyclically Adjusted PB Ratio compare to ESPR and NIKA?
According to the Drug Manufacturers industry distribution chart, Amphastar Pharmaceuticals ranks #330 out of 716 companies for Cyclically Adjusted PB Ratio. This puts Amphastar Pharmaceuticals in the upper half of its industry. The industry median Cyclically Adjusted PB Ratio is 1.76. Amphastar Pharmaceuticals' value of 1.69 is 4% below this benchmark. Historically, Amphastar Pharmaceuticals' own Cyclically Adjusted PB Ratio has ranged from 1.41 to 6.79 over the past decade. While the company's 10-year median is 3.50 vs. the industry median of 1.76, Amphastar Pharmaceuticals has consistently been below the industry average. See the competitive comparison table and distribution chart on this page for a detailed peer-by-peer breakdown.
What is a good Cyclically Adjusted PB Ratio for a Drug Manufacturers company?
The median Cyclically Adjusted PB Ratio among Drug Manufacturers companies is 1.76, based on 716 companies in the industry. Companies in the top quartile (top 25%) have a Cyclically Adjusted PB Ratio significantly above this median, while those in the bottom quartile fall well below. However, Cyclically Adjusted PB Ratio should not be evaluated in isolation — investors should consider it alongside profitability, growth, and financial strength metrics. Amphastar Pharmaceuticals's current Cyclically Adjusted PB Ratio of 1.69 is 4% below the industry median. Use the industry distribution chart on this page to see where any company falls relative to its peers.
What does a high Cyclically Adjusted PB Ratio mean?
A high Cyclically Adjusted PB Ratio can signal that a stock is expensive relative to its fundamentals. Cyclically Adjusted PB Ratio is the ratio of share price to a company's inflation-adjusted book value per share over a 10-year period. View historical data on Amphastar Pharmaceuticals and its competitors. For the Drug Manufacturers industry, the median Cyclically Adjusted PB Ratio is 1.76 — values significantly above this may indicate overvaluation, while values below may suggest a bargain or underlying issues. Amphastar Pharmaceuticals's current Cyclically Adjusted PB Ratio is 1.69, which is 52% below median its own 10-year median of 3.50. However, context matters — high-growth companies often justify higher valuations. Always evaluate alongside other metrics like GF Score™ and GF Value™.
Is Amphastar Pharmaceuticals stock overvalued right now?
Based on GuruFocus' analysis, Amphastar Pharmaceuticals (STU:29A) is currently considered Significantly Undervalued. The stock's GF Value™ is €31.09, compared to a current price of €18.04 — trading 42% below its estimated fair value. The current Cyclically Adjusted PB Ratio is 1.69, which is 52% below median its 10-year median of 3.50 and 4% below the Drug Manufacturers industry median of 1.76. Amphastar Pharmaceuticals' overall GF Score™ is 79/100 with 4 warning signs to review. Investors should evaluate multiple metrics — including profitability, growth, and financial strength — before making a decision.
How is Cyclically Adjusted PB Ratio calculated?
Cyclically Adjusted PB Ratio is calculated from a company's financial statements. For Amphastar Pharmaceuticals (STU:29A), the current Cyclically Adjusted PB Ratio is 1.69 as of Aug. 16, 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 Amphastar Pharmaceuticals (STU:29A) Overvalued in 2026?

Based on GuruFocus' analysis, Amphastar Pharmaceuticals stock appears to be undervalued. The current stock price of €18.04 is trading 42% below its estimated GF Value™ of €31.09. GuruFocus considers Amphastar Pharmaceuticals to be Significantly Undervalued.

Key valuation signals for STU:29A:

  • Cyclically Adjusted PB Ratio: 1.69 (52% below median its 10-year median of 3.50)
  • GF Value™: €31.09 vs. price of €18.04 (42% below fair value)
  • GF Score™: 79/100 with 4 warning signs
  • Industry Position: 4% below the Drug Manufacturers median (#330 of 716)

No single metric tells the full story. See the STU:29A stock analysis page for a complete view including 30-year financials, guru trades, and insider activity.


Amphastar Pharmaceuticals Business Description

Other Exchanges AMPH:USA
Address 11570 6th Street, Rancho Cucamonga, CA, USA, 91730
Amphastar Pharmaceuticals Inc is a bio-pharmaceutical company focusing on developing, manufacturing, marketing, and selling technically challenging generic and proprietary injectable, inhalation, and intranasal products, as well as insulin active pharmaceutical ingredient (or insulin API products. The company's finished products are used in hospital or urgent care clinical settings and are contracted and distributed through group purchasing organizations and drug wholesalers. The company has one reportable segment: pharmaceutical products. Geographically, the business presence of the firm is seen in the United States, China, and France, of which the U.S. accounts for the majority of the revenue.
79GF Score

Get the complete analysis for STU:29A

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

€18.04
Price
€31.09
GF Value