Is day trading a taxable event if I sold on Coinbase, but have never actually "cashed out" and realized USD gains?

For the last few years I have day traded directly on Coinbase. Eventually I transferred all of my coins to my hardware wallet where they are still sitting. I have never actually "cashed out" and then spent that money. I have every coin I have bought since 2013.

However what I have done is bought on coinbase and then sold a few days later for USD, then turned around and used those same USD on coinbase to buy more bitcoin. I have never deposited USD from coinbase to my bank account. I know transferring to a hardware wallet is not a taxable event, but what about when I sold the bitcoins on Coinbase for USD? Is that a gain/loss that has to be reported? Thanks for any help.