A similar thing happened in 2017. No one expected such a huge bull run in the fall of 2017. However, with the steady rise in price during the early part of year, I can't say it was a surprise though.
But its similar also what happen last December of 2013 BTC price 1,150usd down to 300 usd level of December 2014. But i still hoping hoping a bull run this last quarter of this year.