Comprehensive Stock Comparison
Compare Ardelyx, Inc. (ARDX) vs Alkermes plc (ALKS) Stock
Analyze side-by-side fundamentals, valuation, growth, and profitability to decide which stock is the better buy.
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Quick Verdict
| Category | Winner | Why |
|---|---|---|
| Growth | ARDX | 22.1% revenue growth vs ALKS's -5.2% |
| Value | ALKS | Lower P/E (32.0x vs 401.8x) |
| Quality / Margins | ALKS | 16.4% net margin vs ARDX's -14.2% |
| Stability / Safety | ALKS | Beta 0.61 vs ARDX's 0.62, lower leverage |
| Dividends | Tie | Neither pays a meaningful dividend |
| Momentum (1Y) | ARDX | +22.2% vs ALKS's -12.3% |
| Efficiency (ROA) | ALKS | 9.7% ROA vs ARDX's -11.6%, ROIC 14.9% vs -10.8% |
Who Each Stock Is For
Income & stability
Growth exposure
Long-term compounding (10Y)
Sleep-well-at-night portfolio
Defensive / Recession hedge
Business Model
What each company does and how it makes money
Ardelyx is a biopharmaceutical company that develops and commercializes novel medicines for gastrointestinal and cardiorenal diseases. It generates revenue primarily from sales of its FDA-approved drug tenapanor — marketed as IBSRELA for irritable bowel syndrome with constipation and XPHOZAH for hyperphosphatemia in chronic kidney disease patients — along with partnership milestone payments and royalties from international licensing deals. The company's competitive advantage lies in its proprietary NHE3 inhibitor technology platform, which enables development of first-in-class oral therapies targeting specific ion transport pathways with potentially better safety profiles than existing treatments.
Alkermes is a biopharmaceutical company that develops and commercializes medicines for central nervous system disorders and other serious conditions. It generates revenue primarily from product sales of its proprietary drugs like VIVITROL and ARISTADA — which treat addiction and schizophrenia — along with royalties from partnered products and manufacturing services. The company's competitive advantage lies in its specialized drug delivery technologies that enable long-acting injectable formulations, creating significant barriers to entry for competitors.
Revenue Breakdown by Segment
How each company's revenue is distributed across its business units
Financial Metrics Comparison
Side-by-side fundamentals across 2 stocks. BestLagging
Financial Scorecard
ALKS leads in 4 of 6 categories (Financial Metrics, Valuation Metrics). ARDX leads in 1 (Total Returns).
Financial Metrics (TTM)
ALKS is the larger business by revenue, generating $1.5B annually — 3.7x ARDX's $398M. ALKS is the more profitable business, keeping 16.4% of every revenue dollar as net income compared to ARDX's -14.2%. On growth, ARDX holds the edge at +12.3% YoY revenue growth, suggesting stronger near-term business momentum.
| Metric | ARDXArdelyx, Inc. | ALKSAlkermes plc |
|---|---|---|
| RevenueTrailing 12 months | $398M | $1.5B |
| EBITDAEarnings before interest/tax | -$35M | $281M |
| Net IncomeAfter-tax profit | -$57M | $242M |
| Free Cash FlowCash after capex | -$55M | $520,800 |
| Gross MarginGross profit ÷ Revenue | +88.9% | +86.3% |
| Operating MarginEBIT ÷ Revenue | -9.5% | +17.2% |
| Net MarginNet income ÷ Revenue | -14.2% | +16.4% |
| FCF MarginFCF ÷ Revenue | -13.9% | +0.0% |
| Rev. Growth (YoY)Latest quarter vs prior year | +12.3% | -10.6% |
| EPS Growth (YoY)Latest quarter vs prior year | — | -67.0% |
Valuation Metrics
| Metric | ARDXArdelyx, Inc. | ALKSAlkermes plc |
|---|---|---|
| Market CapShares × price | $1.6B | $5.0B |
| Enterprise ValueMkt cap + debt − cash | $1.7B | $4.5B |
| Trailing P/EPrice ÷ TTM EPS | -25.19x | 21.05x |
| Forward P/EPrice ÷ next-FY EPS est. | 401.84x | 32.04x |
| PEG RatioP/E ÷ EPS growth rate | — | — |
| EV / EBITDAEnterprise value multiple | — | 15.89x |
| Price / SalesMarket cap ÷ Revenue | 3.91x | 3.38x |
| Price / BookPrice ÷ Book value/share | 9.46x | 2.79x |
| Price / FCFMarket cap ÷ FCF | — | 9571.39x |
Profitability & Efficiency
ALKS delivers a 13.3% return on equity — every $100 of shareholder capital generates $13 in annual profit, vs $-37 for ARDX. ALKS carries lower financial leverage with a 0.04x debt-to-equity ratio, signaling a more conservative balance sheet compared to ARDX's 1.25x. On the Piotroski fundamental quality scale (0–9), ALKS scores 5/9 vs ARDX's 3/9, reflecting solid financial health.
| Metric | ARDXArdelyx, Inc. | ALKSAlkermes plc |
|---|---|---|
| ROE (TTM)Return on equity | -36.7% | +13.3% |
| ROA (TTM)Return on assets | -11.6% | +9.7% |
| ROICReturn on invested capital | -10.8% | +14.9% |
| ROCEReturn on capital employed | -10.6% | +14.4% |
| Piotroski ScoreFundamental quality 0–9 | 3 | 5 |
| Debt / EquityFinancial leverage | 1.25x | 0.04x |
| Net DebtTotal debt minus cash | $140M | -$518M |
| Cash & Equiv.Liquid assets | $68M | $588M |
| Total DebtShort + long-term debt | $208M | $70M |
| Interest CoverageEBIT ÷ Interest expense | -1.27x | 23.55x |
Total Returns (with DRIP)
A $10,000 investment in ARDX five years ago would be worth $38,081 today (with dividends reinvested), compared to $15,677 for ALKS. Over the past 12 months, ARDX leads with a +22.2% total return vs ALKS's -12.3%. The 3-year compound annual growth rate (CAGR) favors ARDX at 31.5% vs ALKS's 4.0% — a key indicator of consistent wealth creation.
| Metric | ARDXArdelyx, Inc. | ALKSAlkermes plc |
|---|---|---|
| YTD ReturnYear-to-date | +6.5% | +6.5% |
| 1-Year ReturnPast 12 months | +22.2% | -12.3% |
| 3-Year ReturnCumulative with dividends | +127.4% | +12.6% |
| 5-Year ReturnCumulative with dividends | +280.8% | +56.8% |
| 10-Year ReturnCumulative with dividends | +170.7% | -6.7% |
| CAGR (3Y)Annualised 3-year return | +31.5% | +4.0% |
Risk & Volatility
ALKS is the less volatile stock with a 0.61 beta — it tends to amplify market swings less than ARDX's 0.62 beta. A beta below 1.0 means the stock typically moves less than the S&P 500. ALKS currently trades 82.9% from its 52-week high vs ARDX's 78.0% drawdown — a narrower gap to the peak suggests stronger recent price momentum.
| Metric | ARDXArdelyx, Inc. | ALKSAlkermes plc |
|---|---|---|
| Beta (5Y)Sensitivity to S&P 500 | 0.62x | 0.61x |
| 52-Week HighHighest price in past year | $8.40 | $36.32 |
| 52-Week LowLowest price in past year | $3.21 | $25.17 |
| % of 52W HighCurrent price vs 52-week peak | +78.0% | +82.9% |
| RSI (14)Momentum oscillator 0–100 | 46.1 | 39.0 |
| Avg Volume (50D)Average daily shares traded | 4.1M | 1.6M |
Analyst Outlook
Wall Street rates ARDX as "Buy" and ALKS as "Buy". Consensus price targets imply 159.5% upside for ARDX (target: $17) vs 52.8% for ALKS (target: $46).
| Metric | ARDXArdelyx, Inc. | ALKSAlkermes plc |
|---|---|---|
| Analyst RatingConsensus buy/hold/sell | Buy | Buy |
| Price TargetConsensus 12-month target | $17.00 | $46.00 |
| # AnalystsCovering analysts | 16 | 28 |
| Dividend YieldAnnual dividend ÷ price | — | — |
| Dividend StreakConsecutive years of raises | — | 0 |
| Dividend / ShareAnnual DPS | — | — |
| Buyback YieldShare repurchases ÷ mkt cap | 0.0% | 0.0% |
Historical Charts
Charts are rendered on first load. Hover for details.
Chart 1Total Return — 5 Years (Rebased to 100)
| Stock | Mar 20 | Feb 26 | Change |
|---|---|---|---|
| Ardelyx, Inc. (ARDX) | 100 | 432.78 | +332.8% |
| Alkermes plc (ALKS) | 100 | 164.6 | +64.6% |
Ardelyx, Inc. (ARDX) returned +281% over 5 years vs Alkermes plc (ALKS)'s +57%. A $10,000 investment in ARDX 5 years ago would be worth $38,081 today (including dividends reinvested).
Chart 2Revenue Growth — 10 Years
| Stock | 2016 | 2025 | Change |
|---|---|---|---|
| Ardelyx, Inc. (ARDX) | $24M | $407M | +1595.3% |
| Alkermes plc (ALKS) | $746M | $1.5B | +97.9% |
Ardelyx, Inc.'s revenue grew from $24M (2016) to $407M (2025) — a 37.0% CAGR. Alkermes plc's revenue grew from $746M (2016) to $1.5B (2025) — a 7.9% CAGR.
Chart 3Net Margin Trend — 10 Years
| Stock | 2016 | 2025 | Change |
|---|---|---|---|
| Ardelyx, Inc. (ARDX) | -4.7% | -15.1% | -223.3% |
| Alkermes plc (ALKS) | -28.0% | 16.4% | +158.6% |
Ardelyx, Inc.'s net margin went from -5% (2016) to -15% (2025). Alkermes plc's net margin went from -28% (2016) to 16% (2025).
Chart 4P/E Ratio History — 3 Years
| Stock | 2023 | 2025 | Change |
|---|---|---|---|
| Alkermes plc (ALKS) | 13.2 | 19.6 | +48.5% |
Alkermes plc has traded in a 13x–20x P/E range over 3 years; current trailing P/E is ~21x.
Chart 5EPS Growth — 10 Years
| Stock | 2016 | 2025 | Change |
|---|---|---|---|
| Ardelyx, Inc. (ARDX) | -2.8 | -0.26 | +90.7% |
| Alkermes plc (ALKS) | -1.38 | 1.43 | +203.6% |
Ardelyx, Inc.'s EPS grew from $-2.80 (2016) to $-0.26 (2025). Alkermes plc's EPS grew from $-1.38 (2016) to $1.43 (2025).
Chart 6Free Cash Flow — 5 Years
Ardelyx, Inc. generated $-44M FCF in 2025 (+72% vs 2021). Alkermes plc generated $1M FCF in 2025 (-99% vs 2021).
ARDX vs ALKS: Frequently Asked Questions
9 questions · data-driven answers · updated daily
01Is ARDX or ALKS a better buy right now?
Alkermes plc (ALKS) offers the better valuation at 21.0x trailing P/E (32.0x forward), making it the more compelling value choice. Analysts rate Ardelyx, Inc. (ARDX) a "Buy" — based on 16 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 has the better valuation — ARDX or ALKS?
On forward P/E, Alkermes plc is actually cheaper at 32.0x.
03Which is the better long-term investment — ARDX or ALKS?
Over the past 5 years, Ardelyx, Inc. (ARDX) delivered a total return of +280.8%, compared to +56.8% for Alkermes plc (ALKS). A $10,000 investment in ARDX five years ago would be worth approximately $38K today (assuming dividends reinvested). Over 10 years, the gap is even starker: ARDX returned +170.7% versus ALKS's -6.7%. Past returns do not guarantee future results, and the stock with the higher historical return may already have its best growth priced in.
04Which is safer — ARDX or ALKS?
By beta (market sensitivity over 5 years), Alkermes plc (ALKS) is the lower-risk stock at 0.61β versus Ardelyx, Inc.'s 0.62β — meaning ARDX is approximately 2% more volatile than ALKS relative to the S&P 500. On balance sheet safety, Alkermes plc (ALKS) carries a lower debt/equity ratio of 4% versus 125% for Ardelyx, Inc. — giving it more financial flexibility in a downturn.
05Which has better profit margins — ARDX or ALKS?
Alkermes plc (ALKS) is the more profitable company, earning 16.4% net margin versus -15.1% for Ardelyx, Inc. — meaning it keeps 16.4% of every revenue dollar as bottom-line profit. Operating margin tells a similar story: ALKS leads at 17.2% versus -10.1% for ARDX. At the gross margin level — before operating expenses — ARDX leads at 90.3%, 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.
06Is ARDX or ALKS more undervalued right now?
On forward earnings alone, Alkermes plc (ALKS) trades at 32.0x forward P/E versus 401.8x for Ardelyx, Inc. — 369.8x cheaper on a one-year earnings basis. Analyst consensus price targets imply the most upside for ARDX: 159.5% to $17.00.
07Which pays a better dividend — ARDX or ALKS?
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.
08Is ARDX or ALKS better for a retirement portfolio?
For long-horizon retirement investors, Ardelyx, Inc. (ARDX) is the stronger choice — it scores higher on the combination of lower volatility, dividend reliability, and long-term compounding (low volatility (β 0.62), +170.7% 10Y return). Both have compounded well over 10 years (ARDX: +170.7%, ALKS: -6.7%), 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.
09What are the main differences between ARDX and ALKS?
Both stocks operate in the Healthcare sector, making this a peer-level intra-sector comparison — the same macro tailwinds and headwinds will affect both. 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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