1. on increases above 30 after strong oversold levels.
2. Moreover, we see divergence between price and index, with the last reaches higher lows while BTCUSD fell to lower lows.
Just to be clear, I think, we see stop of the sale-off, not the rebound yet. Formally, it will be possible to talk about the rebound after the price growth above previous local highs ($4300). The dynamics of volumes (growth on price fall) speaks about the predominance of sales by now.