How do you calculate and track time value decay in 1DTE SPX iron condors?

At VixShield we calculate and track time value decay in our 1DTE SPX iron condors through a disciplined daily process built on Russell Clark's SPX Mastery methodology. Time value also known as extrinsic value represents the portion of an option's premium above its intrinsic value and is the primary source of profit in our short iron condor positions. Because we trade exclusively one day to expiration contracts placed at the 3:05 PM CST signal our exposure to premium decay is concentrated in the final 24 hours when theta accelerates dramatically. We rely on the Expected Daily Range indicator EDR to select strikes that capture an optimal credit while staying outside the projected move. For the Conservative tier we target a 0.70 credit Balanced aims for 1.15 and Aggressive seeks 1.60 per contract. These credits are almost entirely extrinsic value at entry given our out-of-the-money wing placement. Once filled we monitor decay through our set-and-forget approach without intraday adjustments. Theta time shift becomes relevant only on the rare losing days when we may roll the threatened side forward to one-to-seven DTE during volatility spikes above VIX 16 or EDR greater than 0.94 percent. This temporal martingale mechanic allows the position to harvest additional time value on the rollback once EDR falls below 0.94 percent and price pulls back below VWAP. Our Adaptive Layered VIX Hedge known as ALVH provides protection across three timeframes so that even when decay temporarily stalls during a spike the overall portfolio remains resilient. In backtested results from 2015 to 2025 this framework has produced an approximate 90 percent win rate on the Conservative tier across roughly 18 out of 20 trading days. We track aggregate daily theta capture by comparing entry credit to the position's value at the following close with RSAi ensuring strike precision in under 253 milliseconds. Position sizing remains at a maximum of 10 percent of account balance to keep risk defined from the start. All trading involves substantial risk of loss and is not suitable for all investors. For deeper examples and live signal walkthroughs we invite you to explore the SPX Mastery resources and join our daily 3:05 PM CST workflow at VixShield.com.