Bitcoin is splitting into two. BIP148/ forking and SegWit
I will be explaining things in very VERY simple terms, if you need something more technical go somewhere else/PM me.
Quote from theymos (bitcointalk admin) -> “Personally, I consider it most likely that the split will be negligible and that you won't have to do anything, but it's still a good idea to prepare just in case.”

What will happen on august 1?

BIP148 is happening on 1 august (pretty fancy word)
Tldr-> bitcoin may go bonkers, don’t trust your wallet. Your bitcoins may freeze for 1-2 weeks around 1 august. Bitcoin market cap and value is gonna fluctuate like shit TON A LOT!
There is some chance that BIP148 will result in an economic split of the Bitcoin currency at midnight UTC on Aug 1. By split I mean bitcoins will divide into two types-> the new bitcoins and the classic old bitcoins. These two bitcoins will run on different bitcoin core software. One (new) will be running in the updated version of bitcoin core while the other (old) will be running on the old same bitcoin core.
Note-> These two types of bitcoins will not be exchangeable, regard them as separate currencies. Both will have different market value after the split.
In an ideal case, the old bitcoin shall be neglected and everyone should be using the updated version but since the community is huge and people won’t always have same opinions, both these coins may continue.
Quoting theymos “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.”

What should you do?
You can do the following :-
> Buy some altcoins (LTC / ETH most likely) then buy back the bitcoins after split
> Withdraw your bitcoins from exchanges, export your private keys and write them on paper/cold storage/hardware wallets. I won’t even trust blockchain and coinbase wallets on this as they might freeze your bitcoins one
week before and after 1 august some online wallets may even split your bitcoins without you knowing
> Cash out bitcoins
> Of course, your offline electrum wallets are safe AF
> Visit https://1august.org/ for more info on this

What happens if you do nothing?

If you keep you bitcoins in exchanges like blockchain and coinbase they might restrict transactions for few days around the split
If you keep the private keys offline with you, you can spend that private key in both new and old bitcoins. Its like your bitcoins doubled and split into two... ofcourse one of these will have very low value (most likely)


How to make profit from this situation? (its my own belief and theories, you may not trust me and skip on this)
From what I know, in my knowledge the best thing to do is buying some altcoins right now. Hold those altcoins until bitcoin split then buy the new / old BTC. its your call … I really don’t have any idea which bitcoin will be get higher market cap. If I were to make a guess… I will say the improved new BTCs (this is an uneducated guess).

This is what I am doing/suggest:-
Suppose you have $100 worth bitcoins right now.
I buy $100 worth altcoins (only trusted coins with large market cap like ETH/LTC)
Their value will definitely increase because you’re not the only one buying, a lot of people are.
By august 1, split will have taken place. Bitcoin market value is now divided into two so ofcourse both of bitcoins have lower value than the current bitcoin
Now, you can either wait a week or two and buy back whichever bitcoin you want (note its possible that by one week the old bitcoins just disappear. This is an ideal case is the best possible case)
Or instantly trust on anyone bitcoin and buy those cause the price will skyrocket in few days as it might regain back the market value.



Why the split? Why all this? Why is bitcoin going through his?
Well… recently transactions have become very slow and fees have become so high. Bitcoins transactions have become like auctions…….. the highest fees payer gets faster transaction while other just keep waiting. This is because 1 MB block size is very small to hold the transactions and need to be updated. Hence the new bitcoin core.
After this, you can expect faster transactions and low fees.


What is bitcoin forking, BIP148 and segwit?
Forking as the word sounds is branching the chain. The bitcoin forked into two versions.
Forking though software changes are called UASF (user activated soft fork)
BIP148 is one specific UASF. It’s special because it will split bitcoin by august 1 and if everything goes right it will activate segwit (may take many months… predicted to be activated by novermber)
What you need to know is that activating SegWit is the best thing possible for bitcoins.
SegWit in simple words is a way to modify the block codes of bitcoins by increasing max size of blocks and many other improvements. Great shit tbh.


Important links :-
https://1august.org/ -> knowing about safety measures for your bitcoins
http://segwit.co/ -> Is SegWit activated yet? Maybe yes by November (fingers crossed)
https://www.youtube.com/watch?v=OFfBRzh9HmU -> understanding technicalities of segwit
https://www.google.com/ -> google shit to know more/ PM me

EDIT :-
I forgot to mention,
This has happened once before to another cryptocurrency called ETH. It's split did not banished the old ETH rather it divided into two seperate currencies (ethereum and ethereum classic) with different market value.

End notes:-
I wrote this thread to educate you about upcoming situation with bitcoins, i am no expert but i know little stuff and am pretty active in observing bitcoin and its community
Feel free to suggest changed/corrections in the thread
Feel free to PM me regarding any of this