The comparision with poker and trading may be closer than many think.
Taking the most popular form,Texas Hold Em.
Hands are made from 2 Hole cards unseen by the others, and 5 community cards, seen by all.
The ranking is the same as in all other forms of poker.
The chance of winning is basically determined by your hole cards.
After the hole cards (your entry) a round of betting determines if you play or fold,by betting higher (raising) you can manipulate the number of opponents you are opposing.
The next round is the " flop" 3 cards,if by now with your hole cards you have no chance of forming a decent hand it is very advisable to fold (close).
The last 2 cards are dealt one by one and a round of betting ensues after each is dealt.
Players either fold or a "show" is made to determine the winner.
I would suggest that this game mimicks closely all the requistes of a trader.
Knowing when to enter,having seen 5/7 of the cards determing wheither to continue, and then the same with the remaining cards.
The more knowledgible and expert the player,the more he will win in the long run.Of course there will be losing days,but overall the best player will win.
This comparison is amplified when in tournament play.
For example 200 mplayers start with the same amount of chips, play continues untill a player has lost his chips ,when he is "out".Play continues untill for example there are 30 left,where the payout starts, the lower the number left the higher the reward.
Defense in tournament play is vital, as once you are out,you are out.
You are only playing your opponents not a "house" all though a commision is payable to the provider or if you like a brokerage.