I had some success trading a long/short stock portfolio, but on longer time periods than day trading (holding positions from few weeks to few months). The fun lasted almost 3 years. Then I shorted META from 300 to 100 and felt on top of the world, it was after shorting a bunch of other "covid success stories" like zoom, moderna, carvana, and making 50%+ return on each in a reasonnably concentrated portfolio. The rest of my portfolio was doing ok as well.

As META kept going down I kept adding to my position (meaning shorting more), and then it came back up. I ended up a loser on the position despite being up almost 70% at some point. I couldn't believe in a recovery for the company.

I then thought "never again" and started to trade options so that I would have a more disciplined, guaranteed stop loss. I lost more than 50% of my margin that year and another 50% 6 month later, so I was back below square 1 at the end of it all. We are talking small numbers (maybe losing 15k in total) but an amazing amount of time and energy spent doing all this which generated a lot of stress.