Multiplying odds is why streaks break
Adding trades to a parlay multiplies both the payoff and the chance of a wipeout β and the wipeout wins. Find the survivable stake fraction on the Kelly criterion calculator, and see the long-run ruin odds on the risk of ruin calculator.
The odds of an unbroken streak
Letting the full stack ride across consecutive trades multiplies the payoffs β and the failure odds. The chance of N straight wins at win rate p is simply p^N: a coin's 60% per-trade edge gives 7.8% odds of ten straight, and one loss anywhere in an all-in sequence takes everything accumulated.
The expected value trap: at 60% win rate and even payoffs, each individual trade is +EV, but the ride-everything parlay across ten trades wins 7.8% of the time β the strategy converts a good edge into a lottery ticket, keeping the positive expectancy on paper while making ruin the modal outcome. Kelly-style fractional sizing exists precisely because geometric compounding punishes betting the whole stack even with the odds in your favor.
Where the intuition helps beyond literal parlays: any sequence of full-size correlated bets β five max-size longs during one BTC trend β is a parlay wearing separate tickets. Pricing the streak (0.6^5 β 7.8% for all five to work) reframes "five good setups" as the single compound bet it actually is.