Calculating the valuation of an option trade

[x15g]

I am just starting out with this whole world of "Options Trading", so please excuse me.

I see this trade: FTSE-100 INDEX CALL ESX FEB 20 7700 Exp: 21-Feb-2020
with the following details

Trade Price: 17.00
Settlement Price: 48.50
Short: 50
Valuation: -24,250.00

I am trying to decipher this. So let me explain what I understand so far.
It is a short ftse call option with strike price 7700 with expiration date 21st Feb 2020.
Now, what I don't understand is the difference between trade price and settlement price, what that short 50 means and how it derives to a valuation of -24,250.00.
What does that valuation mean?

 

[MasterOfCoin]

Would suggest, as you are just starting out, that you start by reading the

T2W Guide to Trading: Options by RogerM .

It'll introduce you to all the basics involved with plenty of ideas on where to get more information.

 

[x15g]

Appreciate the reply but it would be nice if someone can put me out of my misery in understanding how that valuation is derived.

 

[MasterOfCoin]

It's the weekend, so while I'm sure one of the forums 'options' experts will reply soon enough, you may need to be patient until the question has clocked up a few more views.

& there's a whole sub-forum on Options to browse while you wait.