i have bought a es option about a week ago at 2435 expiring june 16th and on friday when the es was trading at 2442 the option was worth only 19$ isn't suppose to be every point of the es 50$?
You're confusing options and futures. Which is a good sign that you should not yet be trading either.
The price of the option is determined by the strike price and the time duration. I suspect that you purchased a far out of the money call. You can use the option's delta to determine how much the option price will move, relative to the underlying. You should read up on the basics of options trading. There are plenty of options trading info on the internet.
The option he bought expires in a few days. Everything in the option priceing model are deterministic except for the underlying price and IV, so I suspect the combination of IV change and underlying price change was causing it. To the OP, I suggest you read up on basic option pricing before you trade. Best wishes to both.