Informative ! About this Bitcoin Case which happen in 1st Aug !

Although it hasn't happened before, and it is very undesirable, it is possible for Bitcoin to split into two non-negligible separate currencies.
Why is this possible? / What causes a split?
There is no actual BTC in your Bitcoin wallet: there are only private keys which are used to unlock and then transfer ownership of BTC stored in the Bitcoin system. BTC never actually leaves the Bitcoin system. A split creates a clone of the original cryptocurrency, but with modifications preventing the two cryptocurrencies from actually being the same; after the split, you cannot send coins from one side of the split to the other. After the split, your private key can be used to unlock your coins on both the original system and the modified system.

Source of Article: https://bitcointalk.org/index.php?topic=2012799.0

The large Bitcoin miner Bitmain announced that they might engage in a (nonsensically-named) "user activated hardfork" ("UAHF") shortly after BIP148 activates if BIP148 has any success. This would definitely cause an additional split, resulting in up to three currencies: BIP148-Bitcoin, Bitmain-coin, and (depending on the degree of BIP148's success) status-quo-Bitcoin. As mentioned previously, if you have x BTC before the split, you'll be technically able to claim x of all three of these currencies after the split.
The next time when a split is predicted to possibly happen is therefore August 1, 2017 at midnight UTC.