If card counting in Blackjack works, why same can't work for stock market? Or maybe it can.

The lower the stock goes, the higher the probability it will bounce back eventually. (and reverse)

https://wallstreetodds.com/ could be useful for this type of trading.

#thinkingoutloud

I’m a builder looking for the next challenge. 

Maybe not for every situation and depends on the timeframe, but I would say yes. In other situation it would go down to zero quickly and there is always max and avg consequtive days (and %) stock is going down.
It would be interesting to dig deeper into it and do some backtesting, but it's for another time.

> The lower the stock goes, the higher the probability it will bounce back eventually. (and reverse)

Is this actually true?

one is a game of countable permutations the other is not 

check out

1. Fortune's Formula
2. Beat the Dealer
3. Beat the Market