NDX made a huge recovery after the initial sell off, hitting the weekly BZ and rebounded; I would say the initial up was technical, price is oversold at BB extremes but the subsequent rally was due to NDVA. Price is now supported by the BZ and PZ at the same prices thus a double support.
TBH, I thought the rally was rubbish but price action is looking bullish now. I did say that I am not convinced of the rally; thus it would either be a case of NDX strength supporting the other indices, or NDX to falter and bringing SPX down with it.
The location of such a bullish candle is uncommon to say the least, but I would say that to SPX/DJIA would be better candidates to go short from, while using NDX as reference.