Only if you believe BTC would've been at that same value without the fork.
No matter which competitor "wins", your assets should keep the same total value they had before.
This is wild, wild cryptoland. At the moment both Bitcoin and Bitcoin Cash are rising - so a lot of "free" money (at least in the short term.).
For now, two coins is better than one :p
EDIT: allright, Bitcoin Cash has been declining for a few days now. However, it still has quite a bit of value that has not disappeared from Bitcoin's value.
Bitcoin cash, at the time of writing, looks to be around the 300 USD mark, without BTC having moved much.