---
type: "Topics"
locale: "en"
url: "https://longbridge.com/en/topics/100000000862005.md"
description: "📈 Why Do Stocks Rise on Good News?A catalyst is news that changes investors’ expectations about a company’s future. Merck and Moderna’s positive Phase 3 melanoma trial is a good example. The treatment met its main goal and reduced the risk of cancer returning or death. This creates potential for regulatory submission, approval and future revenue. Investors may therefore believe the companies are worth more. However, good news does not guarantee a rise because the market may have already priced in the expectations.@Captain's Watch"
datetime: "2026-08-20T03:37:03.000Z"
locales:
  - [en](https://longbridge.com/en/topics/100000000862005.md)
  - [zh-CN](https://longbridge.com/zh-CN/topics/100000000862005.md)
  - [zh-HK](https://longbridge.com/zh-HK/topics/100000000862005.md)
author: "[optionspuppy](https://longbridge.com/en/profiles/20627341.md)"
generator: "portal-rs"
---

# 📈 Why Do Stocks Rise on Good News?A catalyst is ne…


### Related Stocks

- [MRNA.US](https://longbridge.com/en/quote/MRNA.US.md)
- [MRK.US](https://longbridge.com/en/quote/MRK.US.md)

## Comments (2)

- **Nicky  · 2026-08-20T04:44:13.000Z**: the priced in caveat is the part most people skip. mrna doubling only took market cap from 25b to 69b, so basically nothing was priced in.
- **Fattycat · 2026-08-20T04:33:32.000Z**: Agreed . Good news does not guarantee a stock price to rise.  Sometime investors find excuses to sell on news, lock in profits.


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> **Disclaimer: This article is for reference only and does not constitute any investment advice.**