How the lists are built
- Today, 5-day and 1-month compare the latest close with the close 1, 5 and 21 trading days earlier.
- YTD compares the latest close with the last close of the previous calendar year.
- Streak counts consecutive closes higher (+) or lower (−) than the day before.
- RS (relative strength) weights the 3-month return twice and adds the 6 and 12-month returns, then ranks every stock scanned from 0 to 99. A 90 means it beat 90% of the list.
Big one-day moves usually have a reason: earnings, guidance, an upgrade or a sector move. Big moves on heavy volume tend to matter more, so check the Volume × column, or the unusual volume screener.
Frequently asked questions
Why is a stock I know missing?
The screener scans about 600 large and popular US stocks and ETFs, not the entire market. Small caps and recent IPOs may not be in the list.
Why do I need an Alpaca key?
US stock prices are licensed data, so they can’t be handed out for free by a website. Alpaca gives anyone a free market-data key that allows 200 requests a minute and returns many stocks per request, which is enough to scan the whole list. Your key is saved only in your browser and is sent only to Alpaca. See how to get a free Alpaca key.
Which stocks does it scan?
About 600 US stocks and ETFs: roughly the S&P 500, popular growth and momentum names, and around 75 of the most traded ETFs. The largest 135 load first; the rest follow automatically a few seconds later.
Is the data real-time?
Alpaca’s free data is 15 minutes behind the market. Daily figures update through the trading day, and the latest candle is the current (unfinished) day while the market is open.