### Comment:
tricky. it certainly doesn't change your long position to short. the collateral required for selling a 172.50 is $250 / contract because it could be exercised at any moment.  
  
 Another way to lock it is buy a 10/4 175put at what you think is the top.

### REPLY:
&gt;Another way to lock it is buy a 10/4 175put at what you think is the top. 
  
 oooh hadn't thought of that. wish I saw this before market closed.  
  
 I ended up selling the $172.50. However looks like it's doing its job of preserving the gains because as Visa dropped before close my total return was pretty constant.

### END.