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Introducing Charm Footprint: Visualizing How Time Decay Pressure Evolves

•Chris
optionscharmtime decaydealer positioningexposureindicator

Charm Footprint: A New Perspective on Time-Decay Pressure

We mentioned in our GEXVEX Post that we were working on a new Charm indicator much better than the per-strike chart which we've been showing. I realized this doesn't really make sense - while gamma and vanna have clear feedback loops per-strike with respect to the underlying price and volatility respectively, charm is all about time decay — how option delta changes as time passes, holding price and volatility constant. To capture these time decay effects as best as possible, we’re excited to introduce a brand new visualization called Charm Footprint.

At its core, Charm Footprint is a visualization of time-decay driven dealer hedging pressure across expiries, and crucially, how that pressure evolves over time. Unlike gamma or vanna, charm isn’t about where price might react. It’s about when dealers are forced to adjust risk simply because time is passing. In this case, we believe it is most important to view large changes in aggregate charm on a day-to-day basis across expiries, rather than per-strike.

From Per-Strike to Footprint

Rather than showing Charm exposure per strike, Charm Footprint shows aggregate charm exposure as a value that evolves over time.

The chart is a scatter plot where:

  • Each dot represents charm exposure for a specific expiry

  • The size of the dot reflects the magnitude of exposure

  • The color reflects the direction of dealer hedging pressure

  • We overlay dots of what that charm exposure was when calculated at previous trading days (T-1, T-2, T-3, etc.)

The result is our Charm Footprint that shows:

  • How charm exposure naturally decays as expiries approach

  • When charm exposure suddenly jumps or collapses

  • How positioning changes reshape time-decay pressure across the curve

This makes it immediately obvious whether what you’re seeing is normal, "expected" time decay flows or a structural change driven by new positioning or unwinds

What Charm Footprint Reveals

Here are a few patterns that become very clear with this view:

  1. Natural Time Decay

When positioning is relatively stable, you’ll see dots slowly drift and shrink as expiries roll down the curve. This is the predictable, mechanical side of charm.

  1. Positioning Shocks

When large players add or unwind positions, charm exposure can change dramatically from one day to the next. In the chart, this shows up as dots that suddenly jump in size or flip direction — even if price and volatility barely moved.

This is where charm can become interesting.

  1. Front-End vs Back-End Pressure

Charm Footprint makes it easy to see whether time-decay pressure is concentrated in very short-dated expiries (often associated with intraday drift) or further out on the curve, where pressure can build quietly before becoming relevant.

Layer with GEX and GEXVEX

GEX, VEX (and thus GEXVEX) help answer where price may react.

Charm Footprint helps show the general expected drift of flows when time itself starts to matter.

Used together, they give a much more complete picture of dealer-driven dynamics.

In summary, you can think of it like this:

  • Gamma and vanna tell you how dealers react to price and volatility.
  • Charm shows how dealers are forced to react to time.

Try It Out

Charm Footprint is now live on our symbol overview page for all premium subscribers with broker connections. You’ll find it alongside our other exposure tools, where it adds a temporal layer to the picture you’re already familiar with.

Happy trading!

– Chris