What does Pre-Market & After-Hours Trading mean?

Pre-market and after-hours trading happen outside the normal 9:30am–4:00pm ET session — prices can move sharply on lower volume before most investors can react.

Regular trading runs 9:30am–4:00pm ET, but some brokers allow pre-market (as early as 4am) and after-hours (until 8pm) trading too. Volume is much thinner in these windows, so prices can swing harder on the same news — earnings are usually released right before or after the regular session for this reason.

Pre-Market & After-Hours Trading example

A company reports earnings at 4:05pm ET and its stock jumps from $100 to $112 in after-hours trading, which runs until 8pm. With few traders around, the spread might be 30 cents instead of the usual 1 cent.

Common beginner mistake

Reading after-hours prices as final. Thin trading exaggerates moves, and the stock can open the next morning well away from where it traded the night before.