SION
Sionna Therapeutics, Inc.
Biotechnology
Market Cap$1.94B
5Y Perf.+214.5%
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Stock Comparison
SION vs RARE
Revenue, margins, valuation, and 5-year total return — side by side.
RARE
Ultragenyx Pharmaceutical Inc.
Biotechnology
Market Cap$2.57B
5Y Perf.-39.1%
SION vs RARE — Key Financials
Market cap, revenue, margins, and valuation side-by-side.
| Company Snapshot | SION | RARE |
|---|---|---|
| Industry | Biotechnology | Biotechnology |
| Market Cap | $1.94B | $2.57B |
| Revenue (TTM) | $0.00 | $669M |
| Net Income (TTM) | $-75M | $-609M |
| Gross Margin | — | 83.6% |
| Operating Margin | — | -83.9% |
| Total Debt | $9M | $1.28B |
| Cash & Equiv. | $58M | $434M |
SION vs RARE — Long-Term Stock Performance
Price return indexed to 100 at period start. Dividends excluded.
SION
RARE
| Stock | Feb 25 | May 26 | Return |
|---|---|---|---|
| Sionna Therapeutics… (SION) | 100 | 314.5 | +214.5% |
| Ultragenyx Pharmace… (RARE) | 100 | 60.9 | -39.1% |
Price return only. Dividends and distributions are not included.
Quick Verdict: SION vs RARE
Each card shows where this stock fits in a portfolio — not just who wins on paper.
Bottom line: SION leads in 4 of 5 categories, making it the strongest pick for profitability and margin quality and capital preservation and lower volatility. As sector peers, any of these can serve as alternatives in the same allocation.
SION
Sionna Therapeutics, Inc.
The Income Pick
SION carries the broadest edge in this set and is the clearest fit for income & stability and long-term compounding.
- beta 1.14
- 73.2% 10Y total return vs RARE's -59.4%
- Lower volatility, beta 1.14, Low D/E 2.8%, current ratio 20.61x
Best for: income & stability and long-term compounding
RARE
Ultragenyx Pharmaceutical Inc.
The Growth Play
RARE is the clearest fit if your priority is growth exposure.
- Rev growth 20.1%, EPS growth 7.3%, 3Y rev CAGR 22.8%
Best for: growth exposure
See the full category breakdown
| Category | Winner | Why |
|---|---|---|
| Quality / Margins | SION | 4.1% margin vs RARE's -91.0% |
| Stability / Safety | SION | Beta 1.14 vs RARE's 1.42 |
| Dividends | Tie | Neither stock pays a meaningful dividend |
| Momentum (1Y) | SION | +236.3% vs RARE's -21.8% |
| Efficiency (ROA) | SION | -21.7% ROA vs RARE's -45.8%, ROIC -204.4% vs -89.4% |
SION vs RARE — Revenue Breakdown by Segment
How each company's revenue is distributed across its business units
Segment breakdown not available.
FY 2025
SION vs RARE — Financial Metrics
Side-by-side numbers across 2 stocks — who leads on profitability, valuation, growth, and risk.
BEST OVERALLSIONLAGGINGRARE
RAREUltragenyx Pharmaceut…
1leads
SIONSionna Therapeutics, …
4leads
6 Total Categories
CATEGORYLEADERvs RAREMETRICS WON
Income & Cash FlowRevenue, margins, and cash flow strength
RARE1/1
Valuation MetricsMultiples, price ratios, and targets
SION1/1
Profitability & EfficiencyROE, ROIC, leverage, and quality scores
SION6/7
Total Returns1Y, 3Y, 5Y total returns with dividends
SION5/6
Risk & VolatilityBeta, volatility, and downside exposure
SION2/2
Analyst OutlookRatings, price targets, and dividends
—
—
Income & Cash Flow (Last 12 Months)
RARE leads this category, winning 1 of 1 comparable metric.
Income & Cash Flow (Last 12 Months)
RARE and SION operate at a comparable scale, with $669M and $0 in trailing revenue.
| Metric | SIONSionna Therapeuti… | RAREUltragenyx Pharma… |
|---|---|---|
| RevenueTrailing 12 months | $0 | $669M |
| EBITDAEarnings before interest/tax | -$89M | -$536M |
| Net IncomeAfter-tax profit | -$75M | -$609M |
| Free Cash FlowCash after capex | -$67M | -$487M |
| Gross MarginGross profit ÷ Revenue | — | +83.6% |
| Operating MarginEBIT ÷ Revenue | — | -83.9% |
| Net MarginNet income ÷ Revenue | — | -91.0% |
| FCF MarginFCF ÷ Revenue | — | -72.8% |
| Rev. Growth (YoY)Latest quarter vs prior year | — | -2.4% |
| EPS Growth (YoY)Latest quarter vs prior year | -28.1% | -17.2% |
RARE leads this category, winning 1 of 1 comparable metric.
Valuation Metrics
SION leads this category, winning 1 of 1 comparable metric.
Valuation Metrics
| Metric | SIONSionna Therapeuti… | RAREUltragenyx Pharma… |
|---|---|---|
| Market CapShares × price | $1.9B | $2.6B |
| Enterprise ValueMkt cap + debt − cash | $1.9B | $3.4B |
| Trailing P/EPrice ÷ TTM EPS | -23.04x | -4.48x |
| Forward P/EPrice ÷ next-FY EPS est. | — | — |
| PEG RatioP/E ÷ EPS growth rate | — | — |
| EV / EBITDAEnterprise value multiple | — | — |
| Price / SalesMarket cap ÷ Revenue | — | 3.82x |
| Price / BookPrice ÷ Book value/share | 5.64x | — |
| Price / FCFMarket cap ÷ FCF | — | — |
SION leads this category, winning 1 of 1 comparable metric.
Profitability & Efficiency
SION leads this category, winning 6 of 7 comparable metrics.
Profitability & Efficiency
SION delivers a -22.9% return on equity — every $100 of shareholder capital generates $-23 in annual profit, vs $-6 for RARE. On the Piotroski fundamental quality scale (0–9), SION scores 5/9 vs RARE's 4/9, reflecting solid financial health.
| Metric | SIONSionna Therapeuti… | RAREUltragenyx Pharma… |
|---|---|---|
| ROE (TTM)Return on equity | -22.9% | -6.1% |
| ROA (TTM)Return on assets | -21.7% | -45.8% |
| ROICReturn on invested capital | -2.0% | -89.4% |
| ROCEReturn on capital employed | -36.4% | -46.4% |
| Piotroski ScoreFundamental quality 0–9 | 5 | 4 |
| Debt / EquityFinancial leverage | 0.03x | — |
| Net DebtTotal debt minus cash | -$50M | $842M |
| Cash & Equiv.Liquid assets | $58M | $434M |
| Total DebtShort + long-term debt | $9M | $1.3B |
| Interest CoverageEBIT ÷ Interest expense | — | -14.49x |
SION leads this category, winning 6 of 7 comparable metrics.
Total Returns (Dividends Reinvested)
SION leads this category, winning 5 of 6 comparable metrics.
Total Returns (Dividends Reinvested)
A $10,000 investment in SION five years ago would be worth $17,324 today (with dividends reinvested), compared to $2,281 for RARE. Over the past 12 months, SION leads with a +236.3% total return vs RARE's -21.8%. The 3-year compound annual growth rate (CAGR) favors SION at 20.1% vs RARE's -17.8% — a key indicator of consistent wealth creation.
| Metric | SIONSionna Therapeuti… | RAREUltragenyx Pharma… |
|---|---|---|
| YTD ReturnYear-to-date | +10.5% | +10.7% |
| 1-Year ReturnPast 12 months | +236.3% | -21.8% |
| 3-Year ReturnCumulative with dividends | +73.2% | -44.5% |
| 5-Year ReturnCumulative with dividends | +73.2% | -77.2% |
| 10-Year ReturnCumulative with dividends | +73.2% | -59.4% |
| CAGR (3Y)Annualised 3-year return | +20.1% | -17.8% |
SION leads this category, winning 5 of 6 comparable metrics.
Risk & Volatility
SION leads this category, winning 2 of 2 comparable metrics.
Risk & Volatility
SION is the less volatile stock with a 1.14 beta — it tends to amplify market swings less than RARE's 1.42 beta. A beta below 1.0 means the stock typically moves less than the S&P 500. SION currently trades 93.2% from its 52-week high vs RARE's 61.7% drawdown — a narrower gap to the peak suggests stronger recent price momentum.
| Metric | SIONSionna Therapeuti… | RAREUltragenyx Pharma… |
|---|---|---|
| Beta (5Y)Sensitivity to S&P 500 | 1.14x | 1.42x |
| 52-Week HighHighest price in past year | $46.46 | $42.37 |
| 52-Week LowLowest price in past year | $11.77 | $18.29 |
| % of 52W HighCurrent price vs 52-week peak | +93.2% | +61.7% |
| RSI (14)Momentum oscillator 0–100 | 59.4 | 66.6 |
| Avg Volume (50D)Average daily shares traded | 365K | 1.8M |
SION leads this category, winning 2 of 2 comparable metrics.
Analyst Outlook
Insufficient data to determine a leader in this category.
Analyst Outlook
Wall Street rates SION as "Buy" and RARE as "Buy". Consensus price targets imply 97.1% upside for RARE (target: $52) vs 6.8% for SION (target: $46).
| Metric | SIONSionna Therapeuti… | RAREUltragenyx Pharma… |
|---|---|---|
| Analyst RatingConsensus buy/hold/sell | Buy | Buy |
| Price TargetConsensus 12-month target | $46.25 | $51.50 |
| # AnalystsCovering analysts | 4 | 33 |
| Dividend YieldAnnual dividend ÷ price | — | — |
| Dividend StreakConsecutive years of raises | — | 1 |
| Dividend / ShareAnnual DPS | — | — |
| Buyback YieldShare repurchases ÷ mkt cap | 0.0% | 0.0% |
Insufficient data to determine a leader in this category.
Key Takeaway
SION leads in 4 of 6 categories (Valuation Metrics, Profitability & Efficiency). RARE leads in 1 (Income & Cash Flow).
Best OverallSionna Therapeutics, Inc. (SION)Leads 4 of 6 categories
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SION vs RARE: Frequently Asked Questions
8 questions · data-driven answers · updated daily
01Is SION or RARE a better buy right now?
Analysts rate Sionna Therapeutics, Inc.
(SION) a "Buy" — based on 4 analyst ratings — the highest consensus in this comparison. The "better buy" depends entirely on your goals: growth investors should weight revenue trajectory, value investors should weight P/E and PEG, and income investors should weight dividend yield and streak.
02Which is the better long-term investment — SION or RARE?
Over the past 5 years, Sionna Therapeutics, Inc.
(SION) delivered a total return of +73. 2%, compared to -77. 2% for Ultragenyx Pharmaceutical Inc. (RARE). Over 10 years, the gap is even starker: SION returned +73. 2% versus RARE's -59. 4%. Past returns do not guarantee future results, and the stock with the higher historical return may already have its best growth priced in.
03Which is safer — SION or RARE?
By beta (market sensitivity over 5 years), Sionna Therapeutics, Inc.
(SION) is the lower-risk stock at 1. 14β versus Ultragenyx Pharmaceutical Inc. 's 1. 42β — meaning RARE is approximately 25% more volatile than SION relative to the S&P 500.
04Which is growing faster — SION or RARE?
On earnings-per-share growth, the picture is similar: Ultragenyx Pharmaceutical Inc.
grew EPS 7. 3% year-over-year, compared to -34. 3% for Sionna Therapeutics, Inc.. Higher growth typically commands a higher valuation multiple — check whether the premium P/E or P/S is justified by the growth rate using the PEG ratio.
05Which has better profit margins — SION or RARE?
Sionna Therapeutics, Inc.
(SION) is the more profitable company, earning 0. 0% net margin versus -85. 4% for Ultragenyx Pharmaceutical Inc. — meaning it keeps 0. 0% of every revenue dollar as bottom-line profit. Operating margin tells a similar story: SION leads at 0. 0% versus -79. 5% for RARE. At the gross margin level — before operating expenses — RARE leads at 83. 8%, reflecting greater pricing power or product mix advantage. Stronger margins indicate durable pricing power, lower cost of revenue, or higher mix of software/services. They are one of the clearest signs of business quality.
06Which pays a better dividend — SION or RARE?
None of the stocks in this comparison currently pay a material dividend.
All are effectively zero-yield and should be held for capital appreciation rather than income.
07Is SION or RARE better for a retirement portfolio?
For long-horizon retirement investors, Sionna Therapeutics, Inc.
(SION) is the stronger choice — it scores higher on the combination of lower volatility, dividend reliability, and long-term compounding (low volatility (β 1. 14)). Both have compounded well over 10 years (SION: +73. 2%, RARE: -59. 4%), confirming both are viable long-term holds — but the lower-volatility option typically results in less emotional selling during corrections. Retirement portfolios generally favour predictability over maximum returns. Consult a financial advisor before making allocation decisions.
08What are the main differences between SION and RARE?
Both stocks operate in the Healthcare sector, making this a peer-level intra-sector comparison — the same macro tailwinds and headwinds will affect both.
In terms of investment character: SION is a small-cap quality compounder stock; RARE is a small-cap high-growth stock. These fundamental differences mean investors should not choose between them on a single metric — the "better stock" depends entirely on which of these characteristics aligns with your investment strategy.
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