IMO, I have two ways to identify a bull run:

1. Correlation between BTC & Alts - Generally on slow days, Bitcoin and alt-coins go hand in hand. But, at that one moment when the bull run is imminent, Bitcoin relieves itself from other alt-coins and gears up for it’s own run. That’s when the correlation between BTC and alt-coins reverses resulting a growth in Bitcoin dominance in the entire cryptocurrency market. So, when this correlation starts diluting, it’s one of the signs for Bitcoin bull run or the entire cryptocurrency market.

2. Keep an eye on Medium Statistics - This is an interesting factor for all those writers on medium. If you are a prominent writer on topics like cryptocurrency, Bitcoin, alt-coins and related stuff, your medium stats will be pretty flat since the beginning of 2018 — i.e. during the bear market. But, when there is a bull run upcoming, you see the stats start growing. Since most of the traffic on medium is via google, this could mean that more retail users are looking for knowledge around cryptocurrency and Bitcoin, who are going to buy Bitcoin and increase the demand — thus resulting in spike in prices. So, if your medium stats shoot up — it’s one of the signs for a bull run for Bitcoin or cryptocurrency market.

Just my two cents on this. Better get going as I continue my live poker sessions.