Risk management is the name of the game!
Yes, I think this could be the end of the line for POW. 2018 might not just be a big year for the transparent and fully compliant cryptocurrencies, it might also be the year of the big shipwrecks for those who are at the opposite end of the spectrum, and if they're POW, probably guaranteed.
That BTC chart is an interesting parallel, but we need to keep in mind that was a 1 year 20x at highs, compared to my Alt portfolio which was a 1 year 1,000x into highs (just a 10x in the last 2 months). The model portfolio posted in May on Bitcoin Forum was a 100x. I didn't have much choice other than proceed with a massive rebalancing.