Why does the price of LTC go down all the way?
It was pumped when the news came out of the deal with the miners to adopt segwit - and then dumped when the whales decided to take their profits.
Nothing much is going to happen with litecoin until they can prove that people actually USE the coin. If they don't use it, segwit etc is useless.
Further more, litecoin won't be the first cryptocurrency to add Segwit to their source code. Some minor coin that i noticed is groestlcoin and it has already adopted the change on their mainnet. it is still in its 3 years and it already has a $1.6 million market cap. The trade is for less than three cents in $ but has been busy growing over the years. Earlier this year, groestlcoin admins inputed some code include Segwit, and probably i think in there 3rd anniversary near the end of March, Segwit was activated.