Exponential Weighted Volatility (EWMA, Exponential Weighted Moving Average) is an approach to volatility calculation. The main objective of the EWMA approach is to closely track the volatility as it changes.

This is an example of sorting functions that allow alphabetical or numerical sorting by a specified column. The functions below put empty values to the end while sorting. 

One of the most useful functions in Excel is a function that shows unique values from a range. There is a native UNIQUE function but it doesn't do the job very well and isn't supported by older Excel versions, so let me present an alternative.

 If you run your VBA code with calculations that affect any cells on your workbook sheets, it is good practice to disable some Excel services to increase the speed of the calculation. 

The VBA script below saves a sheet to xlsx file with today's date in the name.

In spreadsheets with lots of numbers, sometimes it is useful to see what cells are formulas and what numbers are just hard-defined. 

Sometimes it is useful to send a sheet right from Excel just by clicking a button (without manual copying and saving). Here is a VBA function that sends an Excel Sheet via email. 

Black-Scholes-Merton (or BSM) model is the most popular and widely-used option pricing model. Below, there is an example of the calculation of the BSM option price and option Greeks in Excel.