First you need to find out what is in them. I know this is the FTSE thread, and I doubt more than 20% is anything to do with FTSE shares and then it will be particularly themed ones. The FTSE isn't any worse than it was at the start of the year.
Looking a few months ago the low risk ones took a bigger hit than the high risk ones for most banks, as the low risk ones are normally weighted towards Bonds with less Equities, and as Millwall says the bonds took a hammering.
Short answer, no idea. Some people may be able to guess if you tell them what the name of the investment fund is and risk level.