In short
- Most large US companies report outside regular trading hours — either before the market opens (BMO) or after it closes (AMC).
- The US regular session runs 9:30am to 4:00pm Eastern; releases cluster just outside those bounds.
- Across a year of AFTERNS data, after-the-close accounted for 54.8% of reports and before-the-open 45.2% — close to an even split.
When do US earnings releases land?
The US regular session runs 9:30am to 4:00pm Eastern. Earnings land outside it. Before-the-open releases typically arrive in the hours ahead of the bell; after-the-close releases usually land shortly after 4:00pm ET, with the earnings call following later.
| Session | US Eastern | What it means | When the price move shows up |
|---|---|---|---|
| Before the open (BMO) | Ahead of the 9:30am bell | Released before regular trading starts | That day's regular session |
| After the close (AMC) | After the 4:00pm bell | Released once regular trading ends | Extended hours → next regular session |
| Regular session | 9:30am – 4:00pm | Normal trading hours | — |
What do BMO and AMC mean?
BMO stands for Before Market Open: the company releases results ahead of the US regular session. AMC stands for After Market Close: the release comes once the regular session has ended. Both describe a session, not a guaranteed clock time. The exact minute varies by company.
Which session is more common?
AFTERNS counted every US earnings release it collected over a full year and split them by session. After the close is slightly more common, but it is close to an even split — assuming every report lands after the bell will make you miss nearly half of them.
- 54.8%
- After the close (AMC) · 2,399 reports
- 45.2%
- Before the open (BMO) · 1,979 reports
- 4,378
- Reports with a confirmed session
Period: 1 Sep 2025 – 31 Aug 2026 · Sample: 5,005 US earnings reports, of which 4,378 had a confirmed session (627 excluded as unknown) · Source: AFTERNS earnings database
Do price reactions differ by session?
In the same sample, the average next-session move (absolute, direction ignored) was 6.6% for after-the-close reports and 5.7% for before-the-open ones. That gap should not be read as 'AMC causes bigger moves'. Sector composition is mixed in — technology names cluster after the close and move more to begin with. Treat the session as information about when to check, not as a trading signal.
- 6.6%
- After the close · average next-session move
- 5.7%
- Before the open · average next-session move
Absolute values, direction ignored. Same period and sample (AMC n=2,396, BMO n=1,979).
Why report outside regular hours?
Earnings can move a stock sharply. Releasing outside the regular session gives investors and analysts time to read the release and hear the conference call before normal trading resumes. Extended-hours trading, however, has lower liquidity and can be more volatile, so the price right after a release does not reliably carry into the next regular session. The SEC's investor guidance on Investor.gov makes the same point about after-hours trading.
Why is the earnings call at a different time?
The release and the call are not the same event. The press release with the numbers comes first; the earnings call usually starts 30 to 60 minutes later. Because next-quarter guidance is delivered on the call, the initial after-hours reaction to the headline numbers frequently reverses an hour later. Read the numbers, the call, and the next regular session as three separate steps.
Why exact minutes are not shown
AFTERNS labels the session (before the open / after the close) rather than a precise clock time. Many timestamps in calendar feeds are source defaults, not the company's announced time. Until the company states it in an IR notice, the minute is unknown — and the session is the part that actually matters.
Frequently asked questions
What time do US companies report earnings?
Either before the open — ahead of the 9:30am ET bell — or after the close, shortly following the 4:00pm ET bell. Releases during the 9:30am–4:00pm regular session are uncommon.
What is the difference between BMO and AMC?
BMO (Before Market Open) means the release comes ahead of the US regular session; AMC (After Market Close) means it comes after the session ends. Both describe a session rather than a fixed time, so the exact minute varies by company.
Is before-the-open or after-the-close more common?
Over the year to 31 August 2026, 54.8% of reports came after the close and 45.2% before the open — close to an even split. It varies by company and can change between quarters.
Can I get the exact minute of a release?
Not reliably. Calendar feeds often carry placeholder times rather than the company's announced time, so AFTERNS shows the session instead of a false-precision timestamp.
Does the earnings call happen at the same time as the release?
No. The release comes first and the call typically begins 30 to 60 minutes later. Guidance given on the call is often what decides the next day's move.
Related guides
- US Earnings Calendar Subscription · Auto Alerts for Report Dates
- What Is an Earnings Shock? Definition, Threshold and Crash Data
- What Is an Earnings Surprise? Definition, Calculation and Price Data
- What Is Earnings Season? US Timing, Schedule and Real Data
- Earnings Preview: What to Check Before a Report
Does this stock rise or fall on earnings?
See post-earnings price reactions for 1,200+ US stocks, backed by data.
Check it now