Viral and What’s Trending ?

If you going to start viral website, so how you know what's trending, before you even start a website or buying domain...

So, what's trending so you could pick a niche to start on...

that's a good question, but dose the trending still trending or niche going to be changed.

Like now days with Bitcoin, BTC was going up and high which is make it viral topic everyone is talking about ... but not going to be trending for much as it going to be down ...

that's the point.... for other topics ...

Here is some of websites showing what's trending :

Google Trends
Reddit
Buzzfeed Trending
Product Hunt
Twitter Trends Box ( Hash Tags )
Buzzsumo
Aherfs Content Explorer ( NOT FREE - PAID $$$ )
Trend watching ( Paid as well $$$ )
Feedly sort by popularity
YouTube Trending ( Trending Videos )

Here is some reddit trending websites :

Redditlist
Snoopsnoo subreddits