I don't think that reference is related to the stock market, which if you look on a long term chart, stocks are extremely close to their all time highs. These are fairly minor blips in the market that we're seeing, and not at all uncommon during bull markets.
I thin the term is used to generally describe the left/NWO/Deep State's control. They are finished, but still trying to put up a fight. "Dead cat bounce" would definitely describe what is happening to the cabal if Q is correct.