The Metrics That Matter

IV Rank

The single most important number for a premium seller. IV Rank places current implied volatility inside its own 52-week high–low range, on a 0–100 scale.

Above 50 = attractive to sell premium. 80+ = extreme — the richest selling opportunities. One flaw: a single volatility spike distorts the range for a full year, which is why you also check IV percentile.

IV Percentile

The percentage of days in the past 252 trading days that IV was below the current level. It answers "how often is vol actually this high?" — and fixes IV Rank's single-spike distortion, since one crazy day barely moves a 252-day count.

Use the two together: IV Rank tells you where vol sits in its range, IV percentile tells you how unusual that reading really is.

Expected Move

The one-standard-deviation (~68%) move the options market is pricing in, derived from straddle pricing. It's the market's own forecast of how far the underlying can travel — and it typically lines up with the 20–25 delta strikes.

Practical use: your short strikes should sit outside the expected move. If you're selling inside it, you're not getting paid for the risk.

Delta as Probability

Delta doubles as a rough probability gauge: 16 delta ≈ 16% chance of finishing in the money, or about 68% odds of expiring worthless. That's why the flagship setup sells the 16s — it's the market's one-standard-deviation line, and the sweet spot between premium collected and probability kept.

Probability of Profit (POP)

The target metric for every trade. Short premium sold when IV is elevated typically starts at 60–90% probability of profit, versus roughly 50/50 for owning stock. You choose trades by POP, not by whether you "like" the stock.

Probability of Touch

The chance the underlying touches your short strike at any point before expiration — always higher than the chance of expiring there. This is the number that tests your nerves mid-trade, and it's exactly why the system manages at 50% of max profit and exits at 21 DTE instead of sweating every touch.

Buying Power Reduction (BPR)

The capital your broker requires to hold the position. Critical nuance: BPR is not your max loss — it's a constraint that moves. Naked positions' BPR can expand more than 2× under stress (worst case ~3.6×), so size for the stressed requirement, not the entry number.

Beta-Weighted Delta

Your portfolio's total directional exposure, standardized to SPY. It keeps the book roughly delta-neutral. One caution: in volatility events, correlations spike toward 1.0, so beta-weighted delta understates risk right when it matters most — monitor gamma and stress scenarios alongside it.