Stocks represent distributed company ownership. Entrepreneurship (creating companies) has historically been positive value in aggregate.<p>The stock market is the aggregate of all publicly traded entrepreneurship. Trading would be zero sum if and only if the value of that ownership is constant. It is not.<p>A reasonable argument is that nobody knows what the growth rate of the market is and over short timescales it is kind of sort of constant, so you might as well think of it as so. That response is really a knock against high frequency trading and not generally against dabbling in stocks.<p>[Most] High frequency trading and "investing" are basically the same thing on different timescales.<p>Value investing might be characterized as finding undervalued companies, purchasing them, then, as Ben Graham might put it, waiting for Mr. Market to correctly value the company.<p>There are flavors of HFT that aren't easily defensible, but much high frequency trading is basically the same as value investing, using a different definition of "undervalued", which happens to be measured in much smaller time intervals.
Isn't "finding undervalued companies" fundamentally an infrequent activity? I don't see how it's possible to assess the value of a company relative to market price fast enough to make even 10 trades a day.<p>I would say High Frequency Trading is, by definition, not about value, but about price only.
> [Most] High frequency trading and "investing" are basically the same thing on different timescales.<p>Yes, it's basically the same if you take out all the differences. Nothing said so far.<p>Also, investing is clearly not the only activity on markets (speculation, arbitrage, you name it), so let's not over simplify things.<p>Interesting reflection field, though.