You can bank on difficulty rising. Even if btc price goes back to 20k, its a stretch to ever roi on a newly purchased s9
You really shouldn't say stuff like this, if you aren't careful someone might believe you even though you are 100% wrong.
People used to say that about the s7s all the time. An s7 at 10c power was profitable until about 3 days ago....the s9 will be making money for a long time to come.
Ok, say I am wrong, and someone listened and didnt waste their money. It's not like offering FA, or investment advice of any sort.
Profitable versus ever returning investment money
IS NOT THE SAME THING. Spending ~2.5k and waiting till march is more or less an absolutely horrible idea.