Hi Carl,
US stocks trade for longer than our own ASX:
- The pre-market trades from 4 a.m. to 9:30 a.m. ET. The regular market trades from 9:30 a.m. to 4 p.m. ET. The after-hours market trades from 4 p.m. to 8 p.m. ET.
Most US companies reporting after the regular market closes, hence we often see large swings in the after-market which by definition can be volatile as investors are dealing on fresh earnings news. Individual retail investors and institutional investors alike can trade after hours, as long as their brokerage firm offers it. There aren’t any restrictions on who can trade after hours, although retail investors generally weren’t able to trade after hours until mid-1999. This is not available on the ASX, unless dealing in special sizes (generally greater than $1m) and the trade is a crossing between two parties.