Further Development
Analyzing the current trading chart of BTC, I found that BTC reached both my yesterday's targets at $18,647 and $17,260.
Anyway, the momentum is very strong to the downside and my advice is still to watch for selling opportunities with the new downside targets at $15,825 and $15,150.
The main cause of the stronger downside movement was the lack of buyers and overbought/extended condition prior to the drop.
Key Levels:
Resistance: $17,570 and $18,00
Support levels: $ 15,825 and $15,150