How it works
Select, click, compare by size
1
Select stocks text on a webpage.
2
Click the Marketcaper icon or right-click lookup action.
3
Open market cap and latest available stock price. and compare links.
Stocks extension
Stock market cap browser extension
Select a public-company ticker or name on any webpage, click the Marketcaper icon, and see the latest available stock market cap and price context.
Examples to select
NVDAAAPLMicrosoftOracleBRK-B
Public-company market cap
Latest available price
Exchange and stock context
Stock comparison links
Lookup card
Marketcaper Stocks Market Cap Lookup
M
What it does
One clear lookup purpose
The Stocks extension recognizes stock tickers and public-company names, then opens a focused Marketcaper lookup card with market cap, price, and comparison actions.
Selected text
Local first, click to send
Selected text is inspected locally for a possible stocks catalogue match. It is sent to Marketcaper only after you click the icon or use the right-click lookup action.
Permissions
Only what the feature needs
Browser permissions support selection lookup, the context menu, saved preferences, and requests to Marketcaper. They are not used for ads or background page scraping.
Privacy
No account required
The extension does not require a Marketcaper account, does not sell selected text, and does not use selected text for advertising.
Review notes
Why the extension asks for browser permissions
Extension code is bundled in the browser package. Requests to Marketcaper return lookup data, not remote executable scripts.
Content script on webpages
Needed to place the small Marketcaper icon beside selected text. The extension filters selections locally and does not read whole pages.
Context menu
Adds the right-click Marketcaper lookup action for selected text when you prefer not to use the floating icon.
Storage
Remembers your enable or disable preference for selection detection on your browser.
Active tab and scripting
Supports the right-click fallback on the current tab when the content script needs to be loaded safely.
marketcaper.com access
Used only to request a category-scoped lookup after you click the icon or use the context-menu action.
FAQ
Questions before installing
Does the Stocks extension search every Marketcaper category?
No. This extension is category-scoped to stocks, so selections such as BTC are not treated as stock results unless they are real stock catalogue matches.
Can I compare a selected stock with other assets?
Yes. The lookup card links into the stock comparison tool with the selected stock preselected as Asset A.
Other catalogues