fetchOI abstract method

Future<String?> fetchOI({
  1. required String underlyingSymbolId,
  2. required List<String> expiries,
})

Absolute OI (only) as of now, summed across expiries, per strike -- powers the OI Profile indicator's bars, as an alternative to the single feed-provided MarketData.oI. A point-in-time snapshot, so unlike fetchOIChange there's no lookback window to pass.

Resolve to a JSON object:

{
  "calls": {"23450": 87425, ...},
  "puts": {"23450": 3429205, ...}
}

Resolve to null when no data is available.

Implementation

Future<String?> fetchOI({
  required String underlyingSymbolId,
  required List<String> expiries,
});