Options expiring on the current trading day — zero days to expiration. Maximum theta decay but extreme gamma risk. A $1 move can flip a 0DTE from worthless to deep ITM in minutes.
⚡ KEY TAKEAWAY: Maximum theta but maximum gamma. 0DTE is a scalping instrument, not a premium-selling setup. If you sell 0DTE, treat it as a day trade with hard stops.
Why It Matters
0DTE options expire today — maximum theta decay but extreme gamma risk. A $1 stock move can flip a 0DTE from worthless to deep ITM in minutes. They've exploded in popularity for intraday income strategies, but the risk profile is fundamentally different from standard 30-45 DTE premium selling.
How It Works
With zero days remaining, theta has fully accelerated — the option loses value every minute. But gamma is also at maximum. ATM 0DTE gamma can exceed 0.20, meaning delta swings by 20 per $1 move. This creates knife-edge risk: profitable if the stock stays flat, devastating on any meaningful move.
Example
SPY at $580, 10am. You sell the $578 put (0.25 delta) for $0.80. By 3pm with SPY at $580: option decayed to $0.10, profit $70 per contract. But if SPY drops to $575 at 2pm: the put is now $3.00 ITM with delta near -0.90. Your $80 max profit trade is now a $220 loss.
Common Mistakes
Treating 0DTE as 'just faster theta.' The gamma profile is completely different from 30-45 DTE. A 0DTE short put has 5-10x the gamma of a 45 DTE put at the same strike. Also: not using hard stops. In 0DTE, the gap between 'manageable loss' and 'catastrophe' can be 5 minutes.
Options expiring on the current trading day — zero days to expiration. Maximum theta decay but extreme gamma risk. A $1 move can flip a 0DTE from worthless to deep ITM in minutes.
Why does 0DTE matter for premium sellers?
Maximum theta but maximum gamma. 0DTE is a scalping instrument, not a premium-selling setup. If you sell 0DTE, treat it as a day trade with hard stops.
How does 0DTE work?
With zero days remaining, theta has fully accelerated — the option loses value every minute. But gamma is also at maximum. ATM 0DTE gamma can exceed 0.20, meaning delta swings by 20 per $1 move. This creates knife-edge risk: profitable if the stock stays flat, devastating on any meaningful move.
What are common mistakes with 0DTE?
Treating 0DTE as 'just faster theta.' The gamma profile is completely different from 30-45 DTE. A 0DTE short put has 5-10x the gamma of a 45 DTE put at the same strike. Also: not using hard stops. In 0DTE, the gap between 'manageable loss' and 'catastrophe' can be 5 minutes.
