The word "throughout" cannot be used to describe something that is measured at two specific points in time. The word "during" can mean "over the course of" a specific amount of time.

I think either can be used, but throughout would iner that it continuously dropped to that point. One of the definitions of throughout: 2. from the beginning to the end of.

Throughout is wrong because the indicator moves up and down moment by moment throughout the trading day. Here I used "throughout" because I wrote about the activities within the session. The word "during" also means while the session is in progress, but the drop is measured from the beginning of one session to the end of another.

hehehe thanks xarmanla :p It is a typo. Thanks for catching it!!

The market indicator is the "Dow Jones".