English beta
What happened after they mentioned the stock?
Search one ticker and check public comments, SEC 13F filings, insider trades, and simple return calculations without reading raw data first.
Public comments
NVDA
NVIDIA
See what happened after CEOs, politicians, and investors mentioned a stock.
Open data13F institution moves
MU
Micron Technology
Compare which institutions added, reduced, sold, or kept a position.
Open dataInsider trades
TSLA
Tesla
Check SEC Form 4 market purchases and sales without reading raw filings first.
Open dataNot a stock recommendation
WhenBuy summarizes public data and simple calculations. It does not tell you what to buy or sell.
Original sources matter
Use source links, filing dates, and price basis labels to verify the data before relying on it.
Korean version is still primary
The English version starts with the most important entry points first. More pages will be translated gradually.