What makes a coin's mining profitability change so often besides exchange rates?

[CryptoMiner]

I have been using coinwarz for direction on what coins to mine from day to day and trying to figure out the meaning behind some of what I am noticing. Any help is greatly appreciated form you guys. So I noticed that the difficulty of a given coin can rise AND fall through out the day. I thought the difficulty only rises but I guess I was wrong. What causes that? My guess is maybe when miners jump ship and the overall network hash falls. Is that an accurate guess?

Thanks for your help!

[rwessels]

Most coins will automatically adjust difficulty up and down.  There were a few that didn't adjust down quick enough and when miners stopped mining them as much, it became almost impossible to get to the next adjustment and they eventually just died or were hard forked.  With huge multi-coin pools, many coins adjust in huge swings multiple times a day.

[CryptoMiner]

I see. So they lower the difficulty when they are losing network strength to entice people to come back. Something like that? Thanks for taking the time to reply.

[Victoo]

I see. So they lower the difficulty when they are losing network strength to entice people to come back. Something like that? Thanks for taking the time to reply.

Yes. That's what they do.