What is the difference between a conversion and a reversal in options arbitrage, and when is each typically used?

At VixShield we focus our daily trading on 1DTE SPX Iron Condors placed after the 3:10 PM CST close using signals generated by RSAi and the EDR indicator. While our Unlimited Cash System relies on the Iron Condor Command, ALVH hedges, and Theta Time Shift for consistent income, understanding foundational options concepts like conversions and reversals helps traders appreciate the no-arbitrage pricing that underpins every SPX position we take. A conversion is an arbitrage strategy that combines a long put, short call, and long underlying to create a synthetic short position. It is executed when the synthetic short trades at a discount to the actual short stock or futures price, allowing the trader to lock in a risk-free profit as the prices converge at expiration. Conversely, a reversal is the opposite arbitrage: it consists of a short put, long call, and short underlying to create a synthetic long position. Traders deploy a reversal when the synthetic long is priced cheaper than the actual long position, again capturing the mispricing with essentially no directional risk. In practice these opportunities are rare on SPX because its European-style, cash-settled options and enormous liquidity keep put-call parity tightly enforced. Russell Clark emphasizes in the SPX Mastery series that these mechanics matter most when volatility spikes, as seen with our current VIX at 17.95. During such regimes the ALVH hedge layers become especially valuable because VIX calls respond faster to volatility expansion than SPX puts would in a traditional reversal-style hedge. For our Conservative tier targeting a $0.70 credit, Balanced tier at $1.15, or Aggressive tier at $1.60, we rely on EDR projections rather than hunting arbitrage. Still, knowing that conversions and reversals keep fair value anchored gives us confidence that our defined-risk Iron Condors are priced efficiently every trading day. We never use stop losses; instead the Theta Time Shift mechanism rolls threatened positions forward to 1-7 DTE when EDR exceeds 0.94 percent or VIX moves above 16, then rolls them back on a VWAP pullback to harvest additional premium. This temporal recovery has delivered an 88 percent loss-recovery rate in backtests from 2015 through 2025. All trading involves substantial risk of loss and is not suitable for all investors. To see how these concepts integrate with our daily 1DTE workflow, join the SPX Mastery Club for live sessions, EDR indicator access, and direct guidance on executing the full Unlimited Cash System.