Why volatility contracts and expands
Quiet periods tend to be followed by big moves, and big moves by quiet periods. A Bollinger Band squeeze (the bands at their narrowest in months) flags stocks that have gone quiet; traders then watch for a breakout from the range.
- BB width %: the distance between the upper and lower Bollinger Bands (20 days, 2 standard deviations) as a share of the 20-day average.
- Width rank: where today’s width sits among the last 126 days. 0 is the narrowest, 100 the widest.
- ATR %: the 14-day average true range as a share of the price.
- ADR %: the average high-to-low range over the last 20 days.
Frequently asked questions
Does a squeeze tell me which way it will break?
No. It only says volatility is low. Many traders combine it with the trend (for example, price above the 50-day average) and wait for the breakout itself.
Which markets can it scan?
Four, picked with the Market buttons above the table. Crypto (the default) scans the 250 busiest USDT pairs on Binance. Crypto perps scans the 200 busiest USDT perpetual futures on OKX. Both are free public data and need no key. US stocks scans about 600 US stocks and ETFs with your own free Alpaca key, and CME futures scans about 25 front-month CME Group contracts (stock indexes, Treasuries, oil, gas, metals, grains, livestock, currencies and CME bitcoin) with your own free Massive key.
Why do stocks and futures need a key?
Stock and futures prices are licensed data, so a website can’t hand them out for free. Alpaca (for stocks) and Massive (for futures) give anyone a free data key. Your key is saved only in your browser and sent only to that provider. See how to get a free Alpaca key and how to get a free Massive key for futures.
Which stocks does it scan with an Alpaca key?
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?
Crypto and crypto perps are live from Binance and OKX, on daily candles that start at 00:00 UTC (today’s candle is still forming). Alpaca’s free stock data is 15 minutes behind the market, and Massive’s free futures plan is 8 hours delayed. Turn on auto-refresh next to the results to update the table in place every 30 seconds, minute or 5 minutes.