From the price history of Bitcoin, we can learn that Bitcoin price usually surges high during and after Bitcoin halving which takes place every four year. After halving, the price of Bitcoin usually experiences a great surge and investors who already owned Bitcoin before the bull season are tempted to sell and take profit. When the bull market is finally over, the bear market settles in and it last for a very long time too, during the bear market, old and new investors cease the opportunity to accumulate more Bitcoin. That's to say, the best time to buy Bitcoin is during a beer season. Although we can not determine the bottom price of Bitcoin during beer market but it's best to just use the DCA to start accumulating more Bitcoin while expecting the price to reduce more.