Answer:
You did not include the text so i have multiple definitions that may go with what you are reading about
Definition 1 : prevent or obstruct (an anticipated event or action) by taking action ahead of time.
Definition 2 : act in advance of (someone) in order to prevent them from doing something.
Definition 3 : buy up (goods) in order to profit by an enhanced price.
The 3rd definition goes more with a text about history
The 2nd is just preventing someone from doing something ahead of time //Example : Back to the Future
The 1rst definition is like the 2nd one but with events.