Implied probability and expected move · Demo

A session-open expected move board for SPX, SPY or any stock

Recorded in cvforge on June 10, 2026 by ConvexValue · Published July 25, 2026

Expected move computed at the US open for whichever symbol you point it at, with the ATM straddle price, implied range and an expiration ladder.

Exact prompt

Give me a dashboard that calculates expected move for SPX, SPY or stocks at the beginning of the US session

Data cadence

Live U.S. option snapshots, refreshed through the session. Open interest is an end-of-previous-day figure and updates once daily.

Plan requirements

Runs on the free cvforge app and the free data tier (20 requests/hour). No card needed.

What the agent built

  • expected move
  • ATM straddle price
  • expected range distribution
  • implied volatility curve
  • expiration ladder

Fields used

implied_volatility, delta, strike_price, expiration_date, underlying_price, fair_market_value

How to read it

The ATM straddle price is the shortcut this is built on: what it costs to own both sides is approximately what the market thinks the move is worth, which makes expected move readable straight off the chain without a volatility model.

The expiration ladder is what makes it a tool rather than a number. The same underlying has a different expected move for every expiration, and comparing them across the ladder tells you whether the market is pricing a specific near-term event or a general level of movement.

Change it

The prompt is the interface. Ask for a different ticker, a different expiration window, or an extra column in the same sentence style and the agent edits the app in place — you do not start over, and you do not wait for anyone to build it.

Limitations

  • Snapshot data, not a transaction tape: the build reads the chain as it stands, so it cannot attribute a trade to a buyer or a seller.
  • Open interest updates once a day, so an intraday volume/OI comparison is always this session’s volume against yesterday’s open interest.
  • Contract coverage is U.S. listed equities, ETFs and indices. Indices use the I: prefix, for example I:SPX.
  • Current per-contract valuation is Massive fair market value (FMV), a proprietary estimate. cvforge does not provide option bids, asks, midpoint, quote sizes, NBBO or last trades, and FMV is not an executable quote.
  • These are risk-neutral probabilities implied by option prices, not forecasts. They shift with volatility as much as with expectations.
  • Anything derived from implied volatility inherits the model behind it; treat the numbers as a market-implied range, not a measurement.

Related demos

Search focus: expected move calculator at market open. Related: atm straddle expected move tool, daily expected move dashboard. Originally posted on X.