Which knowledge is important for crypto trading, for me the best knowledge are those ideas you gain from those experienced traders that alreaady encountered many tradings, thus it will helps you on your trading on how to handle it properly.
I would be a plus point if you have a practical experience in the crypto world along with market information about the current prices, the speculated prices and the time to sell or buy. Having the knowledge to hold for a specific time and sell again makes the difference between a mature and immature mind. Finally some knowledge about the finance and crypto models is also important.