Your stock is up 12% pre-market. Calm down.

Pre-market runs 4:00 to 9:30 a.m. Eastern and almost nobody is there. Thin volume and wide spreads mean one impatient buyer can move a small cap several percent.

Three checks before you get excited. Volume: if it's under about 1% of a normal day, it's noise. Catalyst: earnings and guidance changes tend to stick, analyst upgrades tend to fade. Sector: if the peers are moving too, there's a real story.

The actual verdict shows up in the first half hour after the bell, when the big orders arrive. We've chased enough 7:45 a.m. candles to know.