models.rb

class Company < Model
  attribute :stock_symbol, type: String
  attribute :name, type: String
  attribute :stock_price, type: Float
  attribute :stock_volume, type: Integer
  attribute :number_of_shares, type: Integer

  has_one :ceo, class_name: 'Person'

  def volume_price
    stock_price * stock_volume
  end
  
  def valuation
    stock_price * number_of_shares
  end
end

class Person < Model
  attribute :name, type: String
end