Right, so where do hedge funds fit in? They hire a lot of people and pay them very well; they sponsor tech events like this: https://www.man.com/pydata-london-59th-meetup. According to your rationale, they don't add any value to society?
And if you add the criteria that they should be a business - how do you think these active investors start? Do you think they just suddenly have $500m in funding and 50 people?
> how profitable can you realistically expect your trading to be? The odds are heavily stacked against the retail trader.
I'd expect it to be hard to become profitable, just like any other kind of business out there. You need to put in a lot of effort, a lot more than what people tend to expect; again, like with any other business.
> Markets have “seasons” and what seems to work in one season can be devastating in another. Markets also change in response to the trading strategies being used (aka “reflexivity”) and “paper testing” can give false confidence.
Sounds like a VC-funded startup to me :) You can make an amazing pitch deck, raise millions in funding, and burn it all to the ground when you realise there are no customers.