fetchAtmStraddleIntraday abstract method

Future<String> fetchAtmStraddleIntraday()

Historical ATM Straddle premium (call + put LTP at the ATM strike), sampled once per minute.

{
  "2025-03-27": [
    { "time": 1721460600000, "atmStraddlePrice": 435.2 },
    ...
  ]
}

Return "{}" when no historical data is available.

Implementation

Future<String> fetchAtmStraddleIntraday();