Even if it's a zero sum game (which it's not), most participants are not quant/algo based. As long as you can beat 50% percentile, you can make a profit.
Sure you may not be as profitable as top quant companies, but do you really mind that much?
Sure you may not be as profitable as top quant companies, but do you really mind that much?
That sounds too much like wishful thinking to me. Furthermore, if someone is really smart enough to beat the market consistently why on earth would they trade just on their own personal account? Work for a hedge fund and use other people's money to leverage your bets.
Alternatively, if you have a strategy that empirically works, and a strategy for identifying such strategies, why take on investors to share the risk? You can scale up your own investment and leverage yourself with less regulatory oversight.
Why on earth do you think the top quant companies will leave alpha on the table for you to snatch up?
It's not so much that they leave alpha on the table, rather that there is so much alpha available, and the capacity constraints and reward profiles are so different for many of them, that individuals can prosper outside of a firm. They just normally don't, because they lack the same training (and because it's very competitive).
Big firms leave tons of (for them) small opportunities on the table, because it's not worth their time.
Similarly, there are people who can regularly beat the market that don't have much to offer large funds because their methods don't scale.
As a simple example, a farmer hedges his wheat crop selling wheat futures. That allows him to reduce some of his risk, thereby allowing him to plant more (i.e. growing the economy). The market marker who bought the wheat futures may be trading multiple commodities. This trade diversifies his risk, allowing him to trade more of other commodities, allowing other farmers to offset more of their risks (i.e. growing the economy). Investment companies or hedge funds enter the market purchasing futures, to diversify their risks, allowing them to invest more in equity markets, which fund companies (i.e. growing the economy).
If my point isn't already clear, markets and trading facilitate the diversification and allocation of risk capital to market participants thereby growing the economy. It's the conduit for capital which does make something.