Overnight vs Regular-Session Profiles: Separate the Auctions

Judge acceptance at the open

Imagine an invented overnight market that moves from 100 to 106 and develops a small node near 105. The previous regular-session value area was 99 to 102. At the next cash open, price begins near 105. The immediate research question is whether the larger daytime auction accepts this higher region.

If price spends time above 104 and volume develops near 105, the overnight repricing is gaining support from a new sample. If price quickly returns below 102 and builds volume there, the higher region may have failed. A brief first-minute spike in either direction is insufficient to settle the question by itself.

Choose an opening observation window before reviewing outcomes. It might be based on time, traded volume, or a defined sequence of tests. The particular rule is less important than applying it consistently and recognizing that different instruments have different opening dynamics.

A gap does not create an obligation

The idea that every gap must fill is a poor substitute for evidence. A gap can reflect new information that changes valuation, a temporary liquidity imbalance, or a price-coordinate issue around contract rollover. Those situations should not be merged into one simplistic expectation.

When studying gap behavior, define whether the gap refers to settlement, prior close, prior regular-session range, or another reference. A futures settlement and the last cash-session print are different values. Mark the chosen reference explicitly so your journal does not change its definition after the outcome.

Also separate overnight distance from overnight participation. A large move on modest volume may deserve a different scenario than the same move supported by sustained activity. Neither is inherently destined to reverse. The distinction tells you what to observe when more participants arrive.

Overnight levels and options references need synchronized inputs

An SPX-based gamma reference plotted on ES requires a contract-aware mapping. During hours when a cash index reference is stale or unavailable, a fresh futures price minus an old index value can mix market direction into the supposed basis. See mapping SPX levels to ES before treating an overnight mapped line as precise.

Do not quietly merge profile volume from different futures contracts around rollover. Record the actual symbol and any continuous-series transformation. A price jump caused by switching contracts is not evidence of an overnight auction rejecting value.

Build a session-comparison journal

Save overnight range, overnight POC, prior regular-session value, opening location, first sustained acceptance, and the next event time. Record the data source and any gap in coverage. If the overnight history is incomplete, the profile should remain explicitly incomplete rather than receive a confident label.

Review similar opening locations together: inside prior value, outside value but inside range, and outside the prior range. Compare what the opening auction adds beyond knowing the gap alone. Include uneventful days, failed scenarios, and sessions you skipped because data quality was inadequate.

The session versus composite guide explains how to choose the broader window. Explore OrderMap's read-only analytics with the available session coverage and account entitlements appropriate to your market; historical availability should be verified rather than assumed.

Reconcile the date label before comparing levels

Imagine a futures session that begins on Sunday evening and belongs to Monday's exchange trading date. A chart grouped by local calendar midnight can split that session into two profiles. Another chart grouped by exchange trading date can keep it intact. Their POCs can differ even with identical underlying trades.

To reconcile the charts, export or inspect the actual start and end timestamps, including offsets. Confirm whether breaks are excluded and whether the profile resets at the evening open or the cash open. A display label such as Monday is insufficient on its own.

Repeat the check around a daylight-saving transition or shortened session. The purpose is not to complicate every morning's routine. It is to establish a configuration you can trust, so later disagreements are investigated as market or data questions rather than caused by an unnoticed calendar boundary.

Explore OrderMap research tools