Those who went with 480/580 at $400 USD will find their cards worth $100. Even if their GPU can make $6 a day for 66 day ROI, their value at risk is 75% of their upfront cost.

Those who went with 1080ti at $700, but make $7 a day has a 100 day ROI. However if crypto crashes 80% tomorrow, their cards are worth $600 at least. That's only 14% of their upfront cost, value at risk is way lower.

If a person can put $10K value at risk. He can buy $71K worth of 1080tis, or he can buy $13.3K worth of 580s. For the same amount of money RISKED (not in upfront capital), he gets much much more hash.