Sionna TherapeuticsSION +5.64%12 WACC % is 10.44% as of Jul. 04, 2026, which is 3% above its 10-year median of 10.11. GuruFocus rates SION with a GF Score™ of 12/100. The stock has 3 warning signs investors should review. Among 1,424 Biotechnology companies, Sionna Therapeutics ranks worse than 57.37% on this metric.
As of today (2026-07-04), Sionna Therapeutics's weighted average cost of capital is 10.44%%. Sionna Therapeutics's ROIC % is -108.59% (calculated using TTM income statement data).
Sionna Therapeutics earns returns that do not match up to its cost of capital. It will destroy value as it grows.
*Note: The beta of this company cannot be obtained because it has a price history shorter than 3 years. It will thus be set to 1 as default to calculate WACC.
For a comprehensive WACC calculation, please access the WACC Calculator.
Sionna Therapeutics (NAS:SION) WACC % Explanation
Because it costs money to raise capital. A firm that generates higher ROIC % than it costs the company to raise the capital needed for that investment is earning excess returns. A firm that expects to continue generating positive excess returns on new investments in the future will see its value increase as growth increases, whereas a firm that earns returns that do not match up to its cost of capital will destroy value as it grows.
As of today, Sionna Therapeutics's weighted average cost of capital is 10.44%%. Sionna Therapeutics's ROIC % is -108.59% (calculated using TTM income statement data).
Sionna Therapeutics earns returns that do not match up to its cost of capital. It will destroy value as it grows.
*Note: The beta of this company cannot be obtained because it has a price history shorter than 3 years. It will thus be set to 1 as default to calculate WACC.
Be Aware
1. GuruFocus uses book value of debt (D) to do the calculation. It is simplified by adding latest one-year quarterly average Short-Term Debt & Capital Lease Obligation and Long-Term Debt & Capital Lease Obligation together.
For companies that report quarterly, GuruFocus combines all of the most recent year's quarterly debt data from the beginning of the year to the year-end and calculates the average.
For companies that report semi-annually, GuruFocus combines all of the most recent year's semi-annual debt data from the start of the year to the year-end and calculates the average.
For companies that report annually, GuruFocus combines the beginning and ending annual debt data from the most recent year and then calculates the average.
2. The WACC formula discussed above does not include Preferred Stock. Please adjust if preferred stock is considered.
3. (Expected Return of the Market - Risk-Free Rate of Return) is also called market premium. GuruFocus requires market premium to be 6%.
4. GuruFocus uses the latest TTM Interest Expense divided by the latest one-year quarterly average debt to get the simplified cost of debt.
Related Terms
Sionna Therapeutics WACC % Historical Data
* Premium members only.
The historical data trend for Sionna Therapeutics's WACC % 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.
For the Biotechnology subindustry, Sionna Therapeutics's WACC %, along with its competitors' market caps and WACC % 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.
Sionna Therapeutics WACC % vs Biotechnology Industry
For the Biotechnology industry and Healthcare sector, Sionna Therapeutics's WACC % distribution charts can be found below:
* The bar in red indicates where Sionna Therapeutics's WACC % falls into.
The weighted average cost of capital (WACC) is the rate that a company is expected to pay on average to all its security holders to finance its assets. The WACC is commonly referred to as the firm's cost of capital. Generally speaking, a company's assets are financed by debt and equity. WACC is the average of the costs of these sources of financing, each of which is weighted by its respective use in the given situation. By taking a weighted average, we can see how much interest the company has to pay for every dollar it finances.
WACC
=
E
/
(E + D)
*
Cost of Equity
+
D
/
(E + D)
*
Cost of Debt
*
(1 - Tax Rate)
1. Weights:
Generally speaking, a company's assets are financed by debt and equity. We need to calculate the weight of equity and the weight of debt.
The market value of equity (E) is also called "Market Cap". As of today, Sionna Therapeutics's market capitalization (E) is $1986.163 Mil.
The market value of debt is typically difficult to calculate, therefore, GuruFocus uses book value of debt (D) to do the calculation. It is simplified by adding the latest one-year quarterly average Short-Term Debt & Capital Lease Obligation and Long-Term Debt & Capital Lease Obligation together. As of Mar. 2026, Sionna Therapeutics's latest one-year quarterly average Book Value of Debt (D) is $8.9512 Mil.
a) weight of equity = E / (E + D) = 1986.163 / (1986.163 + 8.9512) = 0.9955
b) weight of debt = D / (E + D) = 8.9512 / (1986.163 + 8.9512) = 0.0045
2. Cost of Equity:
GuruFocus uses Capital Asset Pricing Model (CAPM) to calculate the required rate of return. The formula is:
Cost of Equity = Risk-Free Rate of Return + Beta of Asset * (Expected Return of the Market - Risk-Free Rate of Return)
a) GuruFocus uses 10-Year Treasury Constant Maturity Rate as the risk-free rate. It is updated daily. The current risk-free rate is 4.485%. Please go to Economic Indicators page for more information. Please note that we use the 10-Year Treasury Constant Maturity Rate of the country/region where the company is headquartered. If the data for that country/region is not available, then we will use the 10-Year Treasury Constant Maturity Rate of the United States as default.
b) Beta is the sensitivity of the expected excess asset returns to the expected excess market returns. Sionna Therapeutics's beta cannot be obtained because it has a price history shorter than 3 years. It will thus be set to 1 as default to calculate WACC.
c) (Expected Return of the Market - Risk-Free Rate of Return) is also called market premium. GuruFocus requires market premium to be 6%.
Cost of Equity = 4.485% + 1 * 6% = 10.485%
3. Cost of Debt:
GuruFocus uses latest TTM Interest Expense divided by the latest one-year quarterly average debt to get the simplified cost of debt.
As of Mar. 2026, Sionna Therapeutics's interest expense (positive number) was $-0 Mil. Its total Book Value of Debt (D) is $8.9512 Mil.
Cost of Debt = -0 / 8.9512 = 0%.
4. Multiply by one minus TTM Tax Rate:
GuruFocus uses the most recent TTM Tax Expense divided by the most recent TTM Pre-Tax Income to calculate the tax rate. The calculated TTM tax rate is limited to between 0% and 100%. If the calculated tax rate is higher than 100%, it is set to 100%. If the calculated tax rate is less than 0%, it is set to 0%.
The latest calculated TTM Tax Rate = 0 / -85.565 = 0%.
Sionna Therapeutics's Weighted Average Cost Of Capital (WACC) for Today is calculated as:
WACC
=
E / (E + D)
*
Cost of Equity
+
D / (E + D)
*
Cost of Debt
*
(1 - Tax Rate)
=
0.9955
*
10.485%
+
0.0045
*
0%
*
(1 - 0%)
=
10.44%
* 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.
Sionna Therapeutics (SION) has a WACC % of 10.44% as of Jul. 04, 2026. The weighted average cost of capital (WACC) is the average rate a company pays to finance assets. View historical data on Sionna Therapeutics and its competitors. This is near median its historical median of 10.11. Over the past decade, Sionna Therapeutics' WACC % has ranged from 10.11 to 10.44. According to the industry distribution chart, Sionna Therapeutics ranks #817 out of 1424 companies in the Biotechnology industry, placing it in the top 57.4%.
Is Sionna Therapeutics' WACC % too high?
Sionna Therapeutics' current WACC % of 10.44% is near median its 10-year median of 10.11. Over the past 10 years, this metric has ranged from a low of 10.11 to a high of 10.44. The Biotechnology industry median WACC % is 10.02. Sionna Therapeutics' value of 10.44% is 4.2% above this industry median. Based on the distribution chart, Sionna Therapeutics ranks #817 out of 1424 companies in the Biotechnology industry, which is below the industry midpoint. Overall, Sionna Therapeutics has a GF Score™ of 12/100, reflecting its overall financial health beyond just this single metric.
How does Sionna Therapeutics' WACC % compare to TYRA and RAPP?
According to the Biotechnology industry distribution chart, Sionna Therapeutics ranks #817 out of 1424 companies for WACC %. This places Sionna Therapeutics in the lower half of its industry. The industry median WACC % is 10.02. Sionna Therapeutics' value of 10.44% is 4.2% above this benchmark. Historically, Sionna Therapeutics' own WACC % has ranged from 10.11 to 10.44 over the past decade. While the company's 10-year median is 10.11 vs. the industry median of 10.02, Sionna Therapeutics has consistently been above 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 WACC % for a Biotechnology company?
The median WACC % among Biotechnology companies is 10.02, based on 1,424 companies in the industry. Companies in the top quartile (top 25%) have a WACC % significantly above this median, while those in the bottom quartile fall well below. However, WACC % should not be evaluated in isolation — investors should consider it alongside profitability, growth, and financial strength metrics. Sionna Therapeutics's current WACC % of 10.44% is 4.2% above 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 WACC % mean?
A high WACC % can signal that a stock is expensive relative to its fundamentals. The weighted average cost of capital (WACC) is the average rate a company pays to finance assets. View historical data on Sionna Therapeutics and its competitors. For the Biotechnology industry, the median WACC % is 10.02 — values significantly above this may indicate overvaluation, while values below may suggest a bargain or underlying issues. Sionna Therapeutics's current WACC % is 10.44%, which is near median its own 10-year median of 10.11. However, context matters — high-growth companies often justify higher valuations. Always evaluate alongside other metrics like GF Score™ and GF Value™.
Is Sionna Therapeutics stock overvalued right now?
Sionna Therapeutics (SION) has a current WACC % of 10.44%. The current WACC % is 10.44%, which is near median its 10-year median of 10.11 and 4.2% above the Biotechnology industry median of 10.02. Sionna Therapeutics' overall GF Score™ is 12/100 with 3 warning signs to review. Investors should evaluate multiple metrics — including profitability, growth, and financial strength — before making a decision.
How is WACC % calculated?
WACC % is calculated from a company's financial statements. For Sionna Therapeutics (SION), the current WACC % is 10.44% as of Jul. 04, 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.
Sionna Therapeutics Inc is a clinical-stage biopharmaceutical company on a mission to revolutionize the current treatment paradigm for cystic fibrosis (CF) patients by developing novel medicines that normalize the function of the cystic fibrosis transmembrane conductance regulator (CFTR) protein to deliver clinically meaningful benefits to CF patients. CF is a progressive and life-threatening genetic disease caused by inherited mutations in the CFTR gene, which heads to insufficient CFTR function. The Company is managed as one operating segment focused on the research and development of cystic fibrosis therapies.
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