How does prediction market expected value compare to casino expected value?

Per $100 wagered, Polymarket costs $1-3 in spread, sportsbooks cost $4.76 in vig, crash games cost $1 in house edge, blackjack costs $0.50, and roulette costs $2.70. The key difference: prediction market EV can be positive if you have better information than other traders. Casino EV is always negative by the fixed house edge. But 87% of Polymarket wallets lose money, suggesting most traders do not actually have an information edge.