QSI Co (XKRX:066310) E10: ₩280.17 (As of Jun. 2026)

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Vera Yuan
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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.
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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.

XKRX:066310 QSI Co Ltd XKRX:066310
77 GF Score
Price ₩7,440.00
GF Value ₩10,262.35
Valuation Modestly Undervalued
! 4 Warning Signs
View Full Analysis

What is QSI Co E10?

QSI Co XKRX:066310 -3.38% 77 E10 is ₩280.17 as of Jun. 2026. GuruFocus rates XKRX:066310 with a GF Score™ of 77/100 and a GF Value™ of ₩10,262.35 (Modestly Undervalued). The stock has 4 warning signs investors should review.

E10 is a concept invented by Prof. Robert Shiller, who uses E10 for his Shiller P/E calculation. E10 is the average of the inflation adjusted earnings of a company over the past 10 years.

QSI Co's adjusted earnings per share data for the three months ended in Jun. 2026 was ₩226.000. Add all the adjusted EPS for the past 10 years together and divide 10 will get our e10, which is ₩280.17 for the trailing ten years ended in Jun. 2026.

During the past 12 months, QSI Co's average E10 Growth Rate was 27.40% per year. During the past 3 years, the average E10 Growth Rate was -1.20% per year. During the past 5 years, the average E10 Growth Rate was 1.00% 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 E10 growth rate using E10 data.

During the past 13 years, the highest 3-Year average E10 Growth Rate of QSI Co was 5.30% per year. The lowest was -14.40% per year. And the median was -1.50% per year.

As of today (2026-08-31), QSI Co's current stock price is ₩7440.00. QSI Co's E10 for the quarter that ended in Jun. 2026 was ₩280.17. QSI Co's Shiller PE Ratio of today is 26.56.

During the past 13 years, the highest Shiller PE Ratio of QSI Co was 129.67. The lowest was 12.27. And the median was 35.58.


QSI Co  (XKRX:066310) E10 Explanation

If a company grows much fast than inflation, E10 may underestimate the company's earnings power. Shiller PE Ratio can seem to be too high even the actual P/E is low.

For the Shiller P/E, the earnings of the past 10 years are inflation-adjusted and averaged. The result is used for P/E calculation. Since it looks at the average over the last 10 years, the Shiller P/E is also called PE10.

The Shiller P/E was first used by professor Robert Shiller to measure the valuation of the overall market. The same calculation is applied here to individual companies.

QSI Co's Shiller P/E Ratio of today is calculated as

Shiller PE Ratio=Share Price/E10
=7440.00/280.17
=26.56

* 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 Shiller P/E Ratio of QSI Co was 129.67. The lowest was 12.27. And the median was 35.58.


Be Aware

Shiller PE Ratio works better for cyclical companies. It gives you a better idea on the company's real earnings power.


QSI Co E10 Related Terms


QSI Co E10 Historical Data

* Premium members only.

The historical data trend for QSI Co's E10 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.

QSI Co E10 Chart

QSI Co Annual Data
Trend Dec16 Dec17 Dec18 Dec19 Dec20 Dec21 Dec22 Dec23 Dec24 Dec25
E10
Get a 7-Day Free Trial Premium Member Only Premium Member Only 200.89 256.03 240.47 234.40 247.15

QSI Co Quarterly Data
Sep21 Dec21 Mar22 Jun22 Sep22 Dec22 Mar23 Jun23 Sep23 Dec23 Mar24 Jun24 Sep24 Dec24 Mar25 Jun25 Sep25 Dec25 Mar26 Jun26
E10 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 219.93 223.16 247.15 268.18 280.17

XKRX:066310 vs LRCX, AMAT, KLAC: E10 Comparison

For the Semiconductor Equipment & Materials subindustry, QSI Co's Shiller PE Ratio, along with its competitors' market caps and Shiller PE 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.


QSI Co Shiller PE Ratio vs Semiconductors Industry

For the Semiconductors industry and Technology sector, QSI Co's Shiller PE Ratio distribution charts can be found below:

* The bar in red indicates where QSI Co's Shiller PE Ratio falls into.


XKRX:066310
77GF Score
QSI Co Ltd XKRX:066310
E10 is just one metric. See GF Score™, valuation, warning signs, and more.
View Full Analysis

QSI Co E10 Calculation

E10 is a concept invented by Prof. Robert Shiller, who uses E10 for his Shiller P/E calculation. When we calculate the today's Shiller P/E ratio of a stock, we use today's price divided by E10.

What is E10? How do we calculate E10?

E10 is the average of the inflation adjusted earnings of a company over the past 10 years. Let's use an example to explain.

If we want to calculate the E10 of Wal-Mart (WMT) for Dec. 31, 2010, we need to have the inflation data and the earnings from 2001 through 2010.

We adjusted the earnings of 2001 earnings data with the total inflation from 2001 through 2010 to the equivalent earnings in 2010. If the total inflation from 2001 to 2010 is 40%, and Wal-Mart earned $1 a share in 2001, then the 2001's equivalent earnings in 2010 is $1.4 a share. If Wal-Mart earns $1 again in 2002, and the total inflation from 2002 through 2010 is 35%, then the equivalent 2002 earnings in 2010 is $1.35. So on and so forth, you get the equivalent earnings of past 10 years. Then you add them together and divided the sum by 10 to get E10.

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, QSI Co's adjusted earnings per share data for the three months ended in Jun. 2026 was:

Adj_EPS= Earnings per Share (Diluted) /CPI of Jun. 2026 (Change)*Current CPI (Jun. 2026)
=226/126.4904*126.4904
=226.000

Current CPI (Jun. 2026) = 126.4904.

QSI Co Quarterly Data

per share eps CPI Adj_EPS
201609 -64.000 101.461 -79.788
201612 79.000 101.561 98.391
201703 8.000 102.851 9.839
201706 86.000 102.611 106.013
201709 112.000 103.491 136.891
201712 -115.000 102.991 -141.240
201803 91.000 104.101 110.572
201806 48.000 104.130 58.307
201809 14.000 105.651 16.762
201812 -118.000 104.351 -143.036
201903 52.000 104.491 62.948
201906 39.000 104.881 47.036
201909 81.000 105.200 97.393
201912 -36.000 105.121 -43.318
202003 70.000 105.354 84.043
202006 105.000 105.112 126.356
202009 -156.000 106.198 -185.809
202012 -4.000 105.765 -4.784
202103 102.000 107.357 120.178
202106 149.000 107.579 175.193
202109 144.000 108.759 167.477
202112 -280.000 109.676 -322.926
202203 88.000 111.848 99.520
202206 310.000 114.072 343.747
202209 190.000 114.715 209.503
202212 169.000 115.179 185.597
202303 442.000 116.507 479.873
202306 221.000 117.182 238.555
202309 -229.000 118.964 -243.489
202312 -141.000 118.837 -150.081
202403 181.000 120.123 190.594
202406 31.000 120.007 32.675
202409 36.000 120.861 37.677
202412 112.000 121.135 116.951
202503 22.000 122.590 22.700
202506 22.000 122.611 22.696
202509 65.000 123.402 66.627
202512 172.000 123.939 175.540
202603 248.000 125.236 250.484
202606 226.000 126.490 226.000

Add all the adjusted EPS together and divide 10 will get our e10.

Frequently Asked Questions Learn more about E10 →
What does a E10 of ₩280.17 mean?
QSI Co (XKRX:066310) has a E10 of ₩280.17 as of Jun. 2026. E10 represents the company's inflation-adjusted earnings per share over a 10-year period. View historical data on QSI Co and its competitors.
Is QSI Co's E10 too high?
QSI Co's current E10 is ₩280.17. Overall, QSI Co has a GF Score™ of 77/100 and is considered Modestly Undervalued, reflecting its overall financial health beyond just this single metric.
How does QSI Co's E10 compare to LRCX and AMAT?
QSI Co's E10 of ₩280.17 can be compared against companies in the Semiconductors industry. See the competitive comparison table and distribution chart on this page for a detailed peer-by-peer breakdown.
What is a good E10 for a Semiconductors company?
A good E10 depends on the Semiconductors industry context. However, E10 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 E10 mean?
A high E10 can signal that a stock is expensive relative to its fundamentals. E10 represents the company's inflation-adjusted earnings per share over a 10-year period. View historical data on QSI Co and its competitors. QSI Co's current E10 is ₩280.17. However, context matters — high-growth companies often justify higher valuations. Always evaluate alongside other metrics like GF Score™ and GF Value™.
Is QSI Co stock overvalued right now?
Based on GuruFocus' analysis, QSI Co (XKRX:066310) is currently considered Modestly Undervalued. The stock's GF Value™ is ₩10,262.35, compared to a current price of ₩7,440.00 — trading 27.5% below its estimated fair value. The current E10 is ₩280.17. QSI Co's overall GF Score™ is 77/100 with 4 warning signs to review. Investors should evaluate multiple metrics — including profitability, growth, and financial strength — before making a decision.
How is E10 calculated?
E10 is calculated from a company's financial statements. For QSI Co (XKRX:066310), the current E10 is ₩280.17 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 QSI Co (XKRX:066310) Overvalued in 2026?

Based on GuruFocus' analysis, QSI Co stock appears to be undervalued. The current stock price of ₩7,440.00 is trading 27.5% below its estimated GF Value™ of ₩10,262.35. GuruFocus considers QSI Co to be Modestly Undervalued.

Key valuation signals for XKRX:066310:

  • E10: ₩280.17
  • GF Value™: ₩10,262.35 vs. price of ₩7,440.00 (27.5% below fair value)
  • GF Score™: 77/100 with 4 warning signs

No single metric tells the full story. See the XKRX:066310 stock analysis page for a complete view including 30-year financials, guru trades, and insider activity.


QSI Co Business Description

Address 17, Cheonheung 8gil, Sungger-eup, Seobuk-gu, Chungnam-do, Cheonan, KOR, 31044
QSI Co Ltd is a South Korea-based company mainly engaged in the manufacture of semiconductor laser diodes (LDs). The product portfolio of the company includes Red Laser diode and Infra-Red Laser diode.
77GF Score

Get the complete analysis for XKRX:066310

E10 is just one metric. See GF Value™, 30-year financials, guru trades, warning signs, and more.

₩7,440.00
Price
₩10,262.35
GF Value