LGND vs RPRX vs RCUS vs XOMA vs MRK

For growth investors, XOMA Royalty Corp.

(XOMA) is the stronger pick with 83. 1% revenue growth year-over-year, versus -4. 3% for Arcus Biosciences, Inc. (RCUS). Merck & Co. , Inc. (MRK) offers the better valuation at 15. 4x trailing P/E (21. 9x forward), making it the more compelling value choice. Analysts rate Ligand Pharmaceuticals Incorporated (LGND) a "Buy" — based on 17 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.

On trailing P/E, Merck & Co.

, Inc. (MRK) is the cheapest at 15. 4x versus XOMA Royalty Corp. at 28. 3x. On forward P/E, Royalty Pharma plc is actually cheaper at 10. 3x — notably different from the trailing picture, reflecting expected earnings growth. The PEG ratio (P/E divided by earnings growth rate) is the most growth-adjusted single valuation metric: Merck & Co. , Inc. wins at 1. 03x versus XOMA Royalty Corp. 's 2. 75x — a reasonable growth-adjusted valuation.

Over the past 5 years, Merck & Co.

, Inc. (MRK) delivered a total return of +70. 2%, compared to -18. 6% for Arcus Biosciences, Inc. (RCUS). Over 10 years, the gap is even starker: XOMA returned +186. 7% versus RPRX's +22. 9%. Past returns do not guarantee future results, and the stock with the higher historical return may already have its best growth priced in.

By beta (market sensitivity over 5 years), Royalty Pharma plc (RPRX) is the lower-risk stock at 0.

45β versus Arcus Biosciences, Inc. 's 1. 95β — meaning RCUS is approximately 330% more volatile than RPRX relative to the S&P 500. On balance sheet safety, Ligand Pharmaceuticals Incorporated (LGND) carries a lower debt/equity ratio of 1% versus 157% for XOMA Royalty Corp. — giving it more financial flexibility in a downturn.

By revenue growth (latest reported year), XOMA Royalty Corp.

(XOMA) is pulling ahead at 83. 1% versus -4. 3% for Arcus Biosciences, Inc. (RCUS). On earnings-per-share growth, the picture is similar: XOMA Royalty Corp. grew EPS 188. 5% year-over-year, compared to -107. 5% for Ligand Pharmaceuticals Incorporated. Over a 3-year CAGR, XOMA leads at 105. 3% annualised revenue growth. 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.

XOMA Royalty Corp.

(XOMA) is the more profitable company, earning 60. 8% net margin versus -142. 9% for Arcus Biosciences, Inc. — meaning it keeps 60. 8% of every revenue dollar as bottom-line profit. Operating margin tells a similar story: RPRX leads at 65. 6% versus -156. 3% for RCUS. At the gross margin level — before operating expenses — RPRX leads at 100. 0%, 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.

The PEG ratio (forward P/E divided by expected earnings growth rate) is the most precise measure of undervaluation relative to growth potential.

By this metric, Merck & Co. , Inc. (MRK) is the more undervalued stock at a PEG of 1. 03x versus XOMA Royalty Corp. 's 2. 75x. A PEG below 1. 5 suggests fair-to-attractive pricing relative to expected growth. On forward earnings alone, Royalty Pharma plc (RPRX) trades at 10. 3x forward P/E versus 36. 7x for XOMA Royalty Corp. — 26. 5x cheaper on a one-year earnings basis. Analyst consensus price targets imply the most upside for XOMA: 30. 2% to $53. 75.

In this comparison, MRK (2.

9% yield), RPRX (1. 3% yield), XOMA (0. 7% yield) pay a dividend. LGND, RCUS do not pay a meaningful dividend and should not be held primarily for income.

For long-horizon retirement investors, Merck & Co.

, Inc. (MRK) is the stronger choice — it scores higher on the combination of lower volatility, dividend reliability, and long-term compounding (low volatility (β 0. 48), 2. 9% yield, +166. 5% 10Y return). Arcus Biosciences, Inc. (RCUS) carries a higher beta of 1. 95 — meaning larger drawdowns in market downturns, which matters significantly when you cannot wait years for a recovery. Both have compounded well over 10 years (MRK: +166. 5%, RCUS: +45. 9%), 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.

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: LGND is a small-cap high-growth stock; RPRX is a mid-cap quality compounder stock; RCUS is a small-cap quality compounder stock; XOMA is a small-cap high-growth stock; MRK is a large-cap deep-value stock. RPRX, XOMA, MRK pay a dividend while LGND, RCUS do not, making them suitable for different income and tax situations. 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.