What Is IV Rank? One Analogy That Makes It Click

If you trade Bull Put Spreads or any premium-selling strategy, you've probably heard "enter when IV is high." But what exactly is IV Rank — and why IV Rank instead of IV itself?

An Analogy That Makes It Click

Think of a convenience store that sells umbrellas for $100 on a normal day.

When a typhoon is coming, the price jumps to $300. IV Rank is high — compared to the past year, umbrellas are expensive right now.

In the dry season, umbrellas go on sale for $60. IV Rank is low — cheaper than usual.

Options work the same way. Implied Volatility (IV) is the umbrella price. IV Rank tells you whether that price is expensive or cheap right now.

---

IV vs. IV Rank — What's the Difference?

IV (Implied Volatility): the raw number — like the umbrella's absolute price.

• SPY's IV today is 18%. Is that expensive or cheap? You can't tell without context.

IV Rank: where today's IV sits within its 1-year range.

• SPY's 1-year IV range: Low 12%, High 35%. Today: 28%.
• IV Rank = (28 - 12) ÷ (35 - 12) × 100 = 70%
• Translation: SPY options are more expensive than 70% of all days in the past year.

IV Rank gives you instant context. No need to look up historical data manually.

---

Why Premium Sellers Care About IV Rank

The premium seller's playbook is simple: sell overpriced options, wait for them to decay.

Sell the umbrella when it's $300. Buy it back when the storm passes and it drops to $100.

• High IV Rank (> 50%): options are expensive, you collect more premium — seller's market
• Low IV Rank (< 20%): options are cheap, thin premium, poor risk/reward — wait

---

A Counterintuitive Finding From Our Backtest

Here's the thing though — we backtested 846 BPS trades, and found something unexpected:

Filtering entries by IV Rank actually made performance worse.

Why? We looked at the IV Rank of winning vs. losing trades — the distributions were nearly identical. Winners had a median IVR of 22.3%, losers had 21.5%. IV Rank had almost no predictive power over individual trade outcomes.

High IV does mean you collect more premium. But filtering for it also means you skip a huge number of profitable low-IV trades. For BPS sellers, waiting for high IV is an opportunity cost problem.

The practical takeaway: IV Rank is an informational signal, not an entry gate. Use it to understand the environment, not to disqualify trades.

---

One Exception: Earnings

Pre-earnings IV is naturally elevated — the market is pricing in expected volatility. After earnings, IV collapses (called IV Crush). For sellers, an IV Crush after earnings can be profitable — but the directional risk from the earnings report itself can't be offset by IV Rank alone.

Don't enter BPS just because IVR is high before a known event.

---

Remember This

IV Rank tells you whether options are expensive. It does not tell you which way the stock will move.

It's one input among several — pair it with Delta for strike selection, DTE for expiration timing, and technical levels for your short put placement.