Comparing two volatility surfaces in the same 3D space
Recorded in cvforge on June 21, 2026 by ConvexValue · Published July 25, 2026
SPY and QQQ surfaces rendered together so the difference between two closely related indices is visible as a gap rather than inferred across two charts.
Exact prompt
I want to compare the IV surface of two stocks in 3d space. Lets start with $SPY and $QQQ.
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.
Fields used
implied_volatility, strike_price, expiration_date, delta, underlying_price
How to read it
Two surfaces in one space is the only way this comparison works. Side by side, with independent axes and colour scales, small differences in level are invisible; overlaid, the gap is the chart.
For SPY against QQQ the expected result is similar shape with QQQ sitting higher — more concentrated, more volatile constituents. The places worth attention are where the shapes differ rather than the levels: a divergence in skew says the two indices are pricing downside differently, which is a stronger statement than one being generally more volatile.
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.
- The surface is drawn from listed strikes and expirations only; gaps between them are interpolation, not data.
- Low-volume, low-open-interest contracts can leave isolated implied-volatility observations that deserve less weight.
Related demos
- AMD IV curve with a volume/OI overlay you can filter
- SPX 3D IV surface: six words, one working chart
- SPY against QQQ on delta and time, overlaid on one axis
Search focus: compare two implied volatility surfaces. Related: spy vs qqq volatility surface, overlay iv surfaces two tickers. Originally posted on X.