'Compute each asset\'s weight in the portfolio by calculating its held
value divided by the total value of all positions.
Each equity\'s value is its price times the number of shares held. Each
futures contract\'s value is its unit price times number of shares held
times the multiplier.'

@property
def current_portfolio_weights(self):

    position_values = pd.Series({asset: ((position.last_sale_price * position.amount) * asset_multiplier(asset)) for (asset, position) in self.positions.items()})
    return (position_values / self.portfolio_value)
