// Calculate implied vol value
openGammaRules.add(new ImpliedVolatilityCalculator());
// At this point, BID, ASK, LAST, MARKET_VALUE, Volume and various Bloomberg implied vol fields are stored in the history.
openGammaRules.add(new FieldHistoryUpdater());
// Filter out non-OpenGamma fields (i.e., BID, ASK, various Bloomberg implied vol fields)
openGammaRules.add(new FieldFilter(
MarketDataRequirementNames.MARKET_VALUE,
MarketDataRequirementNames.SETTLE_PRICE,