Sharing some random tidbits I learned throughout the week.

  • Can use instance_variable_get to check the values of your variables.
    • Sometimes useful for tests.
  • i18n is an abbreviation for internationalization
    • There are 18 letters between the first i and the last n.
  • A dimensional model is a Data warehouse Design Technique using dimensions and facts.
    • A Fact Table is a table containing measurements. For example: Sales, Quantity, Location.
    • A Dimension is a table containing business elements. For example: Shirt, Colour, Size.
    • A Slow Changing Dimension(SCD) is a dimension that changes over time.
      • In Data Warehouses, it is important to keep track of these changes.
  • In Ruby, _ in Numbers are ignored and can be used for readability.
irb(main):001:0> 100_000 == 100000
=> true
  • PORO stands for Plain Old Ruby Object
  • You take a long position when you buy and believe a security will rise in value.
  • To exercise an option means to put into effect the right specified in the contract.
    • Most options are not exercised; expired or closed by opposing positions
  • In The Money refers to an option that will produce a profit if it is exercised. At The Money is when the option’s strike price is identical to the security market price.
  • The Premium is the total cost of an option including the intrinsic value plus the time value and volatility factor.
  • Leverage is the use of borrowed money to increase the rate of return on an investment.
  • The Uptick Rule, also known as Rule 201 requires that every short sale must be entered at a price that is higher than the price of the previous trade.
    • Prevents short sellers from adding to downward momentum
    • By entering price above current bid, order will be fulfilled on an “uptick”
    • Certain liquid securities are excluded from this rule such as market ETFs.