Bitcoin has had many corrections. This correction is taking a bit more time than the last 5 corrections in 2017. The 100 MA is a good indicator for the previous corrections of 2017. The RSI (42) isn't oversold which indicates that the price has some more room to drop to an oversold level. The MACD is flipping which is a bullish sign. The last correction is forming a falling flag which is, when broken through the resistance, a bullish sign.
Since 17/01/2018, bitcoin has been making higher lows which is bullish. The green circle on the picture indicates a breakthrough of a 20-day resistance line which is also a bullish sign.
There are many resistances ($12800, $14400, $17200 and the ATH $19700) which have to be taken out before we can confirm that we are back in a bull market.
I just want to give my humble opinion on some products by doing technical analysis. There may be some minor and/or major flaws. Nobody is perfect and I'm willing to learn from my mistakes through your opinions. Thank you.
Image source: https://www.tradingview.com/
Disclaimer: This is not financial advise.