I have 3 BB on different timeframes, being 9, 21, 126, and they are showing all of them quite some exhaustion to the downside. Also we're on a 9 buy. In the recent past, the 9 candle showed a level where there was a decent reaction the the downside.
Sure it can fail, but i think Bitcoin is pretty elastic and likes to bounce even on a strong downtrend.
Eventually sellers get fewer and bulls push it up. It is not rocket science.