The only reason for this increase is demand we can see that btc has gained a huge demand whenever the price falls it quickly recovers.
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What's the prediction? Historically, every time btc has gone down, alts have suffered even more
This will remain in history current situation btc falls alts suffer, btc rises alts still suffer.
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the best strategy trade until the fork, and then pass all the money to fiat?
Not sure about transferring to alt as that totally depends on you but the current strategy is hold your btc for now and wait until the news spreads of another SegWit when that happens alts will slowly fall. That is the right time to buy alts.