Fixed-fractional sizing means risking a fixed percentage of your account on each trade — classically 1% (some go 0.5%, aggressive scalpers 2%). It's the bedrock of survival because it makes a losing streak survivable: risking 1%, you'd have to lose dozens of trades in a row to do serious damage.
Applying it to 0DTE
The 1% rule is about risk, not position size — so on options it means sizing so that your premium-stop loss equals 1% of the account, not that you buy 1% worth of options. On a $10,000 account, 1% is $100 — so you size your contracts (via the backward-from-risk math) so that hitting your stop loses about $100. The option can cost more than $100 in premium; what's capped at 1% is the loss to your stop.
Why 1% (and why it feels too small)
1% feels tiny when you're confident — which is exactly the point. It keeps any single trade, and any bad run, from mattering, so you're never one trade from ruin and never trading scared. It also makes the math of recovery forgiving: small losses compound slowly, big ones compound catastrophically. Survival first; the returns come from consistency over many small-risk trades, not from betting big.
1% per trade means a 10-loss streak costs ~10% — annoying, survivable, recoverable. Risk 10% per trade and that same streak ends you. Survival is the whole game.
The nuance for small accounts
On a small account, 1% may be less than one contract's worth of sensible risk — a real constraint on very small accounts. The fix is patience and the cheapest viable structure, not abandoning the rule. Fixed-fractional sizing paired with R-thinking is the disciplined core; NoVo's dollar-risk sizing enforces it automatically so no single trade blows the budget.