sclass TradingPosition {
  settable S coin;
  settable bool isLong;
  settable int leverage;
  
  // How much we originally invest in USDT
  settable double marginInvestment;
  
  // How much USDT margin we end up with
  settable double margin;
  
  // How much crypto we bet on
  settable double amount;
  
  settable double openingPrice;
  settable double closingPrice;
  settable double openingFees;
  settable double closingFees;
  
  // Actual price movement during position
  settable TradingCandle candle;
  
  // Signal we acted on (optional)
  settable TradingSignal afterSignal;
  
  double openingFeePercentage() {
    ret doubleRatio(openingFees, margin*leverage);
  }
  
  double priceDifference() {
    ret closingPrice-openingPrice;
  }
  
  double leveragedPriceDifference() {
    ret priceDifference()*leverage;
  }
  
  double expectedPNL() {
    ret (isLong() ? 1 : -1)*leveragedPriceDifference()*amount;
  }
}