After hours trading. The session after the close.

After hours trading runs from 4:00 PM to 8:00 PM ET. The session is dominated by reactions to after market earnings releases and any news that breaks after the close. Volume drops dramatically after 6:30 PM. Most retail traders should not actively trade after hours. The information from the session is more valuable than the trades.

What after hours actually is

After hours trading happens on electronic communication networks (ECNs) after the regular exchange session ends at 4:00 PM ET. The session typically runs until 8:00 PM ET, though some brokers limit access to 6:30 PM or 7:00 PM.

The mechanics are similar to pre market. Limit orders only at most brokers. Wider spreads. Lower volume. Restricted order types.

Volume drops over the course of the session. The first hour (4:00 to 5:00 PM) sees the most activity due to immediate earnings reactions. Volume tapers significantly after 5:30 PM. By 7:00 PM, most stocks have minimal after hours activity.

What moves stocks in after hours

After market earnings releases.

The largest after hours catalyst. Most large companies that report after the close release the press release at 4:00 to 4:30 PM. The conference call typically starts at 5:00 PM. The combination produces the largest after hours moves.

M and A announcements.

Acquisitions and mergers are frequently announced after the close to avoid disrupting regular hours trading. The target stock gaps to the announced price. The acquirer often drops on the dilution or debt.

Late breaking news.

FDA announcements that come after the close. SEC filings that drop after market. Legal rulings. CEO departures. Activist letters released after the close.

Analyst notes for the next morning.

Some analyst upgrades and downgrades publish after the close to give institutional clients time to digest before the next session.

The earnings reaction pattern

The after market earnings move typically unfolds in three phases.

Phase 1. The headline reaction (4:00 to 4:15 PM).

The press release hits. Algorithms read the EPS beat or miss and revenue beat or miss. The stock moves within seconds to reflect the initial interpretation.

Pure quantitative reaction. No nuance yet. The headline numbers drive the initial move.

Phase 2. The conference call reaction (5:00 to 6:00 PM).

The CEO and CFO discuss the quarter, the guidance, the outlook. Analysts ask questions. The market reacts to the qualitative information that goes beyond the headlines.

Often the initial phase 1 move reverses or extends based on the call commentary. A headline beat with weak guidance can reverse the initial pop. A headline miss with strong forward guidance can reverse the initial drop.

Phase 3. The institutional positioning (6:00 PM to next morning).

Institutional desks adjust their positions for the new information. The price stabilizes into a new range that carries into pre market and the next regular session open.

The after hours price at 8:00 PM is usually a reasonable indicator of where the stock will open the next regular session, with adjustments for any additional overnight news.

Why most after hours moves partially reverse

The after hours session is dominated by retail and quick reaction algorithms. Institutional flow is reduced as desks wind down for the day. The combination produces overshoots in both directions.

A stock that pops 15 percent after hours on a strong earnings beat often opens the next regular session at +10 percent because the institutional flow during pre market and the open trims the after hours excitement.

A stock that drops 20 percent after hours on a guidance miss often opens at -15 percent for the same reason. The retail panic that drove the after hours selling gets partially absorbed by institutional buying that sees value.

This partial reversion is the most consistent pattern in after hours trading. Knowing it exists changes how the trader interprets the after hours price.

What to do after the close

Close existing positions if needed.

If a position needs to be closed before the next session, after hours allows execution. The spread cost is higher than regular hours but the position is closed.

Watch the earnings reactions on watchlist names.

Use the after hours moves to plan the next day's trades. A stock that gapped up on earnings becomes a watchlist name for a pull back entry. A stock that gapped down might offer a long entry if the structural setup looks intact and the after hours overshoot is excessive.

Mark the after hours high and low.

These often act as support and resistance the next morning. The after hours high becomes the breakout level for continuation trades. The after hours low becomes the support level for rejection trades.

Update the journal for the trading day.

The post market hour is the natural time to journal the day's trades while the memory is fresh.

When after hours trading makes sense

The same restrictions as pre market apply. Experienced traders with low commission brokers and specific edge in reading earnings reactions can trade the after hours session profitably.

The position size should be smaller than regular hours due to the wider spreads.

The trader needs the ability to take quick losses if the after hours move reverses against the position. The lack of stop loss execution at most brokers means manual management is required.

For most retail, after hours is for watching and planning, not for trading.

The liquidity tapers through the session

4:00 to 5:00 PM. Highest after hours volume.

Immediate earnings reactions. Spreads relatively tight on liquid names. Most after hours trading happens in this hour.

5:00 to 6:30 PM. Moderate volume.

Conference calls happening. Reactions continue. Spreads widen as the session progresses.

6:30 to 8:00 PM. Thin volume.

Volume drops to a fraction of regular hours. Spreads widen significantly. Many stocks have essentially no after hours activity in this window.

The holiday and short session considerations

The market closes early at 1:00 PM ET on the day before some holidays (Thanksgiving Friday, Christmas Eve, day before July 4). After hours sessions on early close days are even thinner than normal.

Some holidays have no after hours session (Thanksgiving Day, Christmas Day, New Year's Day, etc.). The full market is closed.

Friday afternoon sessions tend to be quieter than other weekdays as participants wind down for the weekend. Major Friday after hours news produces larger than normal moves because the typical buyers and sellers are reduced.

Where the audit fits

The audit reads the trade record and identifies whether the trader is taking after hours entries that consistently lose to spread cost and reversion. For most retail the pattern is chasing earnings reactions in after hours. The plan locks the rule that after hours is for closing positions and planning, not for opening new entries unless specific after hours edge has been demonstrated. Five to seven pages.