EL7 Research · Equities — BiopharmaceuticalsPublished 24 August 2026

19 August session: +177.0% Best week in the stock's history: +129.2% Short sellers' one-day losses: 5.5 billion dollars Trading volume: 188.4 million shares (~26 times the average)

Moderna changes the rules of cancer treatment: a 177% session surge — how much was science, and how much was a short squeeze?

On 19 August, Merck and Moderna announced that the first personalised mRNA cancer therapy had succeeded in a Phase 3 Trial, sending the stock to its largest daily gain in history and adding around 45 billion dollars to market capitalisation in a single session. This research analyses that surge by separating it into three strands: what science actually proved, what market mechanics added, and what has now been repriced; based on EL7 database figures.

Executive summary

Before the opening of the Wednesday 19 August session, Merck and Moderna announced that the Phase 3 INTerpath-001 trial had met both endpoints. The individualised neoantigen therapy, called intismeran autogene and added to KEYTRUDA, achieved statistically significant improvement in recurrence-free survival (RFS) and distant metastasis-free survival (DMFS) among 1,137 patients with completely resected melanoma, a type of skin cancer. This is the first time a personalised mRNA-based cancer therapy has passed a Phase 3 trial. The companies have not yet disclosed the magnitude of the effect; hazard ratio values, a measure comparing the risk of an event between the two treatment groups, will be presented at an upcoming medical conference, and only “statistically significant improvement” has been announced so far.

The market did not wait for the details. According to the EL7 price database, the stock gapped up from 62.96 dollars to 116.02, then closed at 174.38. Its daily gain reached +177.0%, the largest in the stock's history, on volume of 188.4 million shares, around 26 times its average daily volume. Short covering, the purchase of shares to close short-selling positions, accounted for a material part of the price move's intensity; investment conviction alone was not behind it. Around 14% of the free float was sold short, and S3 Partners estimated short sellers' losses at around 5.5 billion dollars on that day alone. The stock then fell 23.5% in the following session, ending the week at 145.13 dollars — its best week in history, with a gain of +129.2%.

The third strand is the most important for investors: what is the therapy worth? Morgan Stanley raised its target from 39 to 89 dollars, RBC raised its target from 45 to 130, and Morningstar raised its fair value estimate from 79 to 163. But estimates of the therapy's peak sales diverge tenfold, starting at 5.4 billion dollars (William Blair, for melanoma alone) and reaching 54 billion (Bank of America's unadjusted overall estimate). The EL7 score reflects this divergence clearly: the stock's momentum percentile is 99, while its overall-score percentile is 8; company revenue contracted from 19.3 billion dollars in 2022 to 1.9 billion in 2025, and it still loses more than 3 billion annually. The scientific success is real and rare; translating it into revenue depends on data not yet published, regulatory filings not yet submitted, and the ability to manufacture a personalised treatment for each patient.

This part of the paper is open to EL7 Pro members and to free members who use one of this month's free papers on it. The paper goes on to analyse the numbers, the causes and what they mean for investors, with tables, charts and sources.

November

4/4

Free papers this month · of 4

Renews 1 December

Keep reading for free

Create a free account and read this paper in full

A free account gives you 4 full research papers every month. Or subscribe to EL7 Pro for full access to more than 300 papers.

Create a free account

$700 per year · or $99 per month

...