Do you consider a competent poker player a "gambler"? If yes, I'm okay with calling the act of trading that as well: both are (risk controlled) finite resource bets on a stochastic process, based on the limited ability to predict future outcomes of that process.
If, on the other hand, a competent poker player is
not a gambler, while a trader is, I would like to hear what makes predictions of the 'poker' process different from predictions of the 'market' process. Or, if both of them are gamblers, but neither of them has a chance to be EV+ in your view, then I'd like to see an explanation of why a competent poker player beats an incompetent time after time, (almost) independent of the cards that have been dealt. Been there myself, lost some money in the process
Poker is not a pure game of chance in the same way that a slot machine is a pure game of chance. (I've added enough disclaimers about cheating in prior posts, so mentally insert them where appropriate)
I don't know exactly what mechanism makes trading a game of pure chance, but the evidence shows that it must be.
The first way we know is that because if a strategy existed which consistently resulted in EV+, then one single entity could follow it and eventually own the entire market, at which point it's no longer market. Markets continue to exist, therefore no EV+ strategy exists.
The other way we know it's a game of pure chance is because when enough data is collected on the lifetime behavior of all traders, the results are consistent with playing a game of chance, with about the number of outliers one would expect given the sample size (every once in a while 20 random coin flips will come up all heads in a row).
I should also clarify that I'm talking about gains relative to the overall market. When the entire market is moving up due to the addition on money from external sources, it's easy for individual traders to see patterns that
look like successful strategies, but aren't in fact.
Imagine 100 gamblers playing slot machines that start out at 99.5% payout, then as they continue to play the operators gradually increase the payout past 100% to 110%, then lower it back down to 100% and finally back to where it started.
That's what the infusion of the Baby Boomer's 401k money did to the market, and also to the perceptions of the people involved in it.
Every strategy that appeared to work from the early 1980s until the mid 2000s only did so because the market had been temporarily turned into a positive sum game by tax policy and other regulatory manipulation.
It was never real or sustainable.