On November 15, 2018, BTC hard forked. It's the first Hash War, a fight for blocks. This is a basic rundown about Hash Wars that's basic and gives you the basic idea.
Basically, the Bitcoin Cash hard forked, it split into two groups. One group is Bitcoin Cash ABC, which stands for "Adjustable Blocksize Cap", is lead by Roger Ver. The other is the one Craig Wright started, Bitcoin SV or "Satoshi's Vision".
Craig Wright wanted to split, claiming that he's Satoshi and that his Bitcoin is the true Bitcoin. He wants to have his coin be the only coin, but that's not what Satoshi wanted. On November 3rd, 2018, he sent this letter to Roger Ver:
As you can tell, a not-very-nice letter.
ABC is most likely to stay like the original Bitcoin Cash.
They've been fighting over Hash Rate. If one side has 51% or more, they can shut the other person down, so no one can do anything with that person's coin. Obviously, if no one can do anything with a coin, it loses value.
On November 18th, SV got close. SV got above 40% Hash Rate. On the 19th it got over 51%, but didn't attack, and later in the day dropped to 18%.
Websites where you can see how the Hash War is going are:
http://hashwars.cash/ This is a fun, star-war-themed chart that's fun, has nice music you can dance to, and gives you the basic idea.
(This is a screenshot from this morning)
https://cash.coin.dance/ Here you can see the hash rates, mining pool, and more detailed.
(And this is a screenshot of a section of coin dance from this morning)
I hope this was helpful.