Retention-window per-zone LMP and signed zone-minus-RTO basis, USD/MWh. Positive...

{ "body": { "minLevelSamples": 48, "referenceHours": 168, "windowHours": 168 }, "bodyType": "json", "method": "POST", "type": "http" }

{ "example": { "ageSeconds": 120, "asOf": "2026-10-09T18:00:00-04:00", "availability": { "emptySelection": "points is an empty array when this window has no print. That is not a zero price. HTTP 503 is only an empty store.", "maxReferenceHours": 2160, "maxReturnedPoints": 10000, "maxWindowHours": 2160, "pagination": null, "referenceWindowIncomplete": false, "selection": "points", "storeHasPrints": true }, "basisDefinition": "zoneLmp - rtoLmp", "canonicalZones": [ "BGE", "PEPCO", "DOM", "PSEG", "JCPL" ], "coverage": { "clockNote": "Each t keeps the offset stored on that observation. A PJM local day is the America/New_York calendar day, including DST. Do not truncate a UTC timestamp to a date. The 2026-11-05 local day starts at 2026-11-05T05:00:00Z (EST, UTC-5) because US fall-back in 2026 is 2026-11-01.", "duplicateTimestampGroups": 0, "firstT": "2026-10-09T18:00:00-04:00", "lastT": "2026-10-09T18:00:00-04:00", "lookbackCount": 48, "maxReturnedPoints": 10000, "maxWindowHours": 2160, "minLevelSamples": 48, "newestStored": "2026-10-09T18:00:00-04:00", "oldestStored": "2026-09-20T00:00:00-04:00", "referenceHours": 168, "referenceStart": "2026-10-02T18:00:00-04:00", "referenceWindowIncomplete": false, "retentionDays": 90, "returnedCount": 1, "timezone": "America/New_York" }, "disclaimer": "Descriptive statistics only. Not a forecast, signal, or trading recommendation. Aggregated from public market sources. Freshness depends on the last successful background poll.", "granularityNote": "Descriptive per-zone granularity only. A signed basis shows which zones are premium or discount to RTO. It is not a forecast and it is not evidence that a forecast improved.", "localDay": null, "localDayEnd": null, "localDayStart": null, "maxAgeSeconds": 10800, "minLevelSamples": 48, "observationCount": 1, "omittedConfiguredZones": [ "COMED" ], "points": [ { "rtoLmp": 40, "rtoStatus": "ok", "t": "2026-10-09T18:00:00-04:00", "zones": { "BGE": { "basis": 6, "deviation": 4.5, "deviationStatus": "ok", "level": 1.5, "levelStatus": "ok", "lmp": 46, "priceStatus": "ok" }, "DOM": { "basis": 0, "deviation": 0, "deviationStatus": "ok", "level": 0, "levelStatus": "ok", "lmp": 40, "priceStatus": "ok" }, "JCPL": { "basis": -1, "deviation": 0, "deviationStatus": "ok", "level": -1, "levelStatus": "ok", "lmp": 39, "priceStatus": "ok" }, "PEPCO": { "basis": null, "deviation": null, "deviationStatus": "missing_basis", "level": null, "levelStatus": "insufficient_history", "lmp": null, "priceStatus": "missing_zone" }, "PSEG": { "basis": -5, "deviation": -1, "deviationStatus": "ok", "level": -4, "levelStatus": "ok", "lmp": 35, "priceStatus": "ok" } } } ], "polledAt": "2026-10-09T18:00:00-04:00", "product": "pjm-nowcast", "provenance": { "actuals": "observations.rto_lmp joined to zonal_lmps.lmp on observation_id", "alignment": "zone LMP and RTO LMP come from the same observation row", "deviation": "basis minus level when both exist", "insufficientHistory": "level and deviation are null when fewer than minLevelSamples prior finite basis values exist. The basis is still returned.", "level": "median of finite basis values with timestamp strictly before t and inside referenceHours. An even count averages the two central values. Prints that share t are excluded.", "missing": "null means that print has no finite value. Numeric 0 is a real zero, including a zero RTO LMP or a zero basis.", "notDerivedFrom": [ "zonal p95-p05", "history zonalSpread.points.spread", "nowcast_snapshots.spr_nc" ], "source": "background poller of the public PJM markets page. Not an official PJM feed." }, "referenceHours": 168, "requestedWindowHours": 168, "servedZones": [ "BGE", "PEPCO", "DOM", "PSEG", "JCPL" ], "sign": { "negative": "discount to RTO", "null": "missing price or insufficient history. Null is not zero.", "positive": "premium to RTO", "unit": "USD/MWh", "zero": "flat to RTO. A numeric zero is a real zero, not a missing print." }, "stale": false, "summary": { "aggregateSpreadNote": "p95 minus p05 of finite LMPs among servedZones on the newest returned print, USD/MWh. Comparison only. It is not a zone basis and it is not copied onto every zone.", "servedZoneAggregateSpread": 9.499999999999993, "standouts": { "discount": [ { "basis": -5, "zone": "PSEG" }, { "basis": -1, "zone": "JCPL" } ], "flat": [ { "basis": 0, "zone": "DOM" } ], "legend": "Ranked by signed basis on the newest returned print. Positive and negative lists are separate. A missing zone is not ranked as zero. Dispersion is not a rank.", "missingOnLatest": [ "PEPCO" ], "premium": [ { "basis": 6, "zone": "BGE" } ] }, "zones": { "BGE": { "descriptiveWindowMedian": 6, "latestBasis": 6, "latestDeviation": 4.5, "latestLevel": 1.5, "nBasis": 1, "nInsufficientHistory": 0, "nLevel": 1, "nMissing": 0 }, "DOM": { "descriptiveWindowMedian": 0, "latestBasis": 0, "latestDeviation": 0, "latestLevel": 0, "nBasis": 1, "nInsufficientHistory": 0, "nLevel": 1, "nMissing": 0 }, "JCPL": { "descriptiveWindowMedian": -1, "latestBasis": -1, "latestDeviation": 0, "latestLevel": -1, "nBasis": 1, "nInsufficientHistory": 0, "nLevel": 1, "nMissing": 0 }, "PEPCO": { "descriptiveWindowMedian": null, "latestBasis": null, "latestDeviation": null, "latestLevel": null, "nBasis": 0, "nInsufficientHistory": 0, "nLevel": 0, "nMissing": 1 }, "PSEG": { "descriptiveWindowMedian": -5, "latestBasis": -5, "latestDeviation": -1, "latestLevel": -4, "nBasis": 1, "nInsufficientHistory": 0, "nLevel": 1, "nMissing": 0 } } }, "timezone": "America/New_York", "unit": "USD/MWh", "unsupportedCanonicalZones": [], "windowHours": 168, "windowMode": "trailing_hours" }, "type": "json" }