Free OA prep
Card Markets
A dealer quotes a market on the sum of five cards, some face down. Calculate the expected value quickly, trade when the quote is off and pass when it's fair. The card EV game used in trading interviews. Sign in and your best final balance goes on the leaderboard.
Cards run A=1 to K=13, so each hidden card is worth 7 on average. If the expected total is above the ask, buy; below the bid, sell; in between, pass. Size up when the edge is big. Pick a difficulty or set your own rules.
Difficulty
2-3 hidden, 15s a round. The ranked setup.