When (if) I should consider cashing in (selling) shares to realize capital gains?
How about this rule? Sell 10% of your shares every time they double in price.  (of course, only buy stocks that repeatedly double in price)
Below is an instruction that describes a task. Write a response that appropriately completes the request.

### Instruction:
When (if) I should consider cashing in (selling) shares to realize capital gains?

### Response:
How about this rule? Sell 10% of your shares every time they double in price.  (of course, only buy stocks that repeatedly double in price)