Rearranging A column in Excel

[deezina07]

Hello,

I am stuck at a problem for awhile. I will highly appreciate if someone can help me out with this.

I have a column with "Buy" and "Sell" Signals (three variables, that is, "Buy, "Sell", or ""). However, Buy signals appear multiple times before a sell signal, and sell signal appears multiple times before a buy signal. I want to rearrange the column such that
1) the first signal that I receive in my column is a buy signal, that is, ignore all cells (Let them remain empty) that read "Sell" before the first buy
2) After the first buy signal appears, ignore all the buy signals before a sell signal appears.
3) When a sell signal appears, ignore all the cells until the next buy signal appears
4) Repeat such that every buy signal is followed by an empty cell until a sell signal appears, and subsequently, every sell signal is followed by an empty cell until a buy signal appears.

I would highly appreciate if someone can help me with this.

Also, I have attached a sample file in which I show that I want Column A to look like Column B.

[SimonLock]

I've added a helper column in column C, which indicates either 1 or 0 depending on whether most recent signal was Buy or Sell.

Then in column D I have added either Buy or Sell when the indicator changes.