Why is Alvotech stock rallying today?

The market is likely reacting less to the filing itself than to the removal of a binary overhang that had been compressing terminal value. For a biosimilar platform, the first re-rating usually comes when investors stop assigning a near-zero probability to manufacturing remediation failure; that matters because the equity can gap well before any approval decision if the review clock is now credible. The move also signals that the stock was crowded on the wrong side of an execution reset, so a modest amount of good news can force a sharp short-covering and momentum chase.

The second-order winner is Teva, but the benefit is asymmetric and mostly in sentiment/optionality rather than immediate P&L. A cleaner regulatory path for partnered biosimilars improves Teva’s perception as a commercialization platform for late-cycle branded erosion, which can modestly support multiple stability even if the direct dollar contribution is small near term. Less obvious: if Alvotech’s manufacturing remediation is accepted, contract manufacturing and supply-chain partners also de-risk, which can accelerate the rest of the pipeline by reducing the probability that future programs inherit the same facility discount.

The key risk is that this is still a six-month catalyst, not a completed de-risking. FDA review can pause for quality questions, and the market is probably extrapolating a clean approval sequence that is not guaranteed; any further information request would likely unwind a good portion of the move because the stock’s recent lows imply a fragile holder base. Contrarian read: the rally may be underpowered if investors are only valuing one or two products, because the real option is in proving the manufacturing flywheel and unlocking a broader biosimilar slate over 12-24 months, not just this round of filings.