My rating decreased by about 200 points after COOK84

I am quite new to codechef and after COOK84 , my rating increased to 1580, but it showed that I haven’t participated in COOK84…I knew that there was some problem with the questions, but all of sudden…I saw that today my codechef rating dropped to 1398 (rating before COOK84).
Why did it happen, is the contest been declared unrated, or still they are experimenting with our ratings.
@admin…Please check what’s wrong with my rating and it still shows that I haven’t participated in COOK84.

Please check the forum before posting Q. The exact Q has been answered before.

They are still testing, its just that they made sure that the “testing results” are not publicly highlighted. Once testing is done, final ratings will be updated.