The End of Day Range program evaluates late-session option-selling structure to identify potential SPX support and resistance into the close. These levels provide references for assessing price behavior and late-session trading opportunities.
Significant put selling can establish potential support, while significant call selling can establish potential resistance. When both boundaries are present, they form a two-sided range. Traders can then evaluate whether SPX remains inside the structure, approaches a boundary, or moves through it.
Beginning at 2:30 PM Eastern, the program reassesses seller-defined structure every ten minutes. Successive assessments help traders follow how the boundaries develop as option activity and market conditions change.
Begin with the Market Intelligence assessment, then use the Flow Map to verify the seller activity behind the levels. EOD Range Insights displays those boundaries alongside the SPX price path, helping traders examine how price has responded and whether the structure is stable or changing.
A complete range requires both support and resistance. If only put-selling support or call-selling resistance is present, traders have a one-sided reference rather than a confirmed containment range. The missing boundary matters when evaluating a position that depends on both sides holding.
Support and resistance can overlap rather than form a clearly separated range. EOD Range Insights displays overlapping levels with a gold overlap level and a shaded ten-point zone. Traders should examine price behavior and the underlying activity rather than treat the overlap as a conventional two-sided range.
Buyer activity adds directional-pressure context that can support or challenge containment. GEX Phase Delta Flow helps traders examine gamma conditions and directional flow, while the GEX Trend Monitor shows directional strength. Lower GTS is generally more supportive of containment; stronger directional conditions can increase pressure on one boundary.
Price repeatedly challenging a level, changing seller activity, or strengthening directional pressure can give traders reasons to reassess containment. GTS challenge conditions and the supporting flow should be evaluated together. A published boundary is a reference point, not a guaranteed barrier.
Abrupt late-session flows and strong directional pressure can change a previously stable range as SPX approaches settlement. Traders should reassess the boundaries and supporting conditions rather than assume earlier containment will persist through the close.