Research note · 7 October 2026
Amgen Inc AMGN
SHORT price $413.08 · base case $342.43 · expected +28% over 540 days
The call
Amgen trades at $413.08 against a base-case DCF value of $342.43 and a probability-weighted value of $298.49, a gap of 17.1% and 27.7% respectively. The market prices in the bull case: the bull DCF of $410.79 is essentially at the price, meaning the stock is valued as if MariTide Phase 3 succeeds and biosimilar erosion is manageable. The filing itself warns of accelerated sales erosion on Prolia and XGEVA following RANKL patent expiry, IRA-mandated Medicare price setting on ENBREL (22% lower net selling price in Q2 2026) and Otezla (effective January 2027), and MFN pricing pressure.
Why the opportunity exists, in the desk's view: a narrative overshoot.
What decides the case
- Biosimilar erosion on Prolia/XGEVA
- IRA and MFN price-setting impact on net selling prices
- MariTide Phase 3 outcomes
What breaks the case
| Shock to the base case | Value per share | vs price |
|---|---|---|
| Base case as planned | $342.43 | -17% |
| Starting cash flow 10% higher | $384.69 | -7% |
| Growth 5 points higher every year | $440.47 | 7% |
| Discount rate 100bp higher | $284.70 | -31% |
| Starting cash flow 10% lower | $300.18 | -27% |
| Growth 5 points lower every year | $260.43 | -37% |
| Cost of debt 200bp higher | $321.95 | -22% |
The base case equals the price at a 7.5% discount rate, or if every year's growth were +3.7% points different. Thresholds, not forecasts.
Model-authored research with an editorial gate; every figure traces to the filing or a stated assumption and every calculation was reproduced before publication. Not investment advice. Do not redistribute.