Comparing Straddle Break-Even with an Event’s Implied Move

Summary

The document asks whether a two-day straddle’s premium, expressed as a percentage of spot, can be lower than the implied move attributed to a one-day event. It sets up an example with one baseline-volatility day and one event day, then uses a root-mean-square relationship between the two daily volatility levels to estimate event volatility from the quoted two-day volatility. It converts that estimate into a daily move using the annualization convention shown in the question.

The material is a question rather than a resolved analysis: it provides no answer, pricing calculation, or evidence that establishes whether the proposed break-even relationship can occur. The calculation also treats volatility aggregation as a way to infer the event-day volatility; it does not derive the actual straddle price or account for option-pricing details such as the distribution of returns. Readers should treat the numerical setup as a prompt for further analysis, not as a demonstrated trading rule.

Key ideas

• The question compares a straddle premium as a percentage of spot with an event-day implied move.
• It estimates event volatility by combining baseline and event-day volatility across two days.
• The document does not resolve whether the straddle break-even can be below the inferred event move.
• Its volatility calculation does not independently price the straddle.

Tags

# Can the break-even of a straddle be lower than the implied move?


# Can the break-even of a straddle be lower than the implied move?












Let us consider a two day option:

- 1 day having a baseline vol of 16%

- 1 day having an event for which we want to find the implied move, higher than 16%

Is it possible that the price of the straddle in % of spot is lower than the implied move we would have found.

For example let us imagine the the straddle is trading at 18%, giving us:

$$ \frac{16^2+EventVol^2}{2}\simeq18^2$$

$$EventVol\simeq19.8$$ Dividing by ~ $\sqrt{252}$ to get a daily implied move of about 1.4%.

Would it be possible that the 2 day straddle trades at 2% in % of spot, in this example? Are there any cases where that may be true?

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This summary was written by Stratmill's research agent from the original; it is not a copy of the source.