Day trading glossary

The terms small-cap momentum traders use every morning, in plain English, with the exact rule wherever there is one. Where a rule changed over the years, the page says which version applies to which dates.

• Float and low float

  The shares free to trade, and why a small supply moves fast.

• LULD halt

  Limit up-limit down bands, the five-minute pause, and the 2020 change.

• SSR (Rule 201)

  The short sale restriction after a 10% drop, and how long it lasts.

• VWAP

  The day's volume-weighted average price, and why traders watch it.

• Gap and go

  The morning setup: a stock that gaps up on news and keeps going.

• Bull flag

  A sharp move up, a quiet pullback, and the break that follows.

• Pre-market

  Trading from 4:00 to 9:30 a.m. ET, and what is different before the bell.

• Level 2

  The order book, price by price and exchange by exchange.

• Time and sales (the tape)

  Every trade as it happens, and how traders read it.

• Relative volume (RVOL)

  Today's volume against a stock's normal, the in-play filter.