Seventeen providers sell VRP or IV/RV data through an API: eleven for US options or broker accounts and six for crypto venues. Market, formula and price decide which one fits. Tradytics and ApexVol are lower-cost choices for a current US spread. FlashAlpha Growth fits when you also want full-chain GEX, on US options or on CME bitcoin and ether futures. For BTC or ETH options on offshore venues such as Deribit, use a crypto provider.
Provider guide / Volatility and variance risk premium
Published by FlashAlphaUpdated November 12, 2026
How to choose in three steps
Start with the market. US options, index proxies, broker accounts, CME crypto futures and offshore crypto venues each have their own providers.
Match the formula and its timing. IV minus trailing RV, IV² minus RV² and a forward outcome are different numbers, known at different times.
Then compare price and use rights. Three providers offer a free key, and API access alone does not grant redistribution rights.
Providers compared17by market, formula, price and access
Measures under the VRP label4trailing, forecast, forward and variance
Outcome after a +5 spread−4vol points, in the worked example
Free API keys3Oanor, CryptoDataAPI and CryptoGamma
Eleven APIs cover US options and broker accounts
Eleven providers cover US markets or a broker platform. Two suit narrower jobs: Oanor covers four volatility indices (VIX, VXN, OVX, GVZ) rather than option chains, and Futu and moomoo serve an existing broker account. Each price is for the plan that returns the listed API feature, at the stated billing period.
Eleven US-market or broker-platform candidates, including FlashAlpha.
Provider
Metric
Access and price
Best fit
FlashAlpha
ATM IV from a selected listed expiry minus trailing RV over 5, 10, 20 and 30 sessions. The full VRP endpoint adds variance, put-side, call-side and GEX-conditioned readings.
Broad session research at a lower entry price. The free selected MCP tools are not full REST.
Futu / moomoo
Contract-specific IV − the underlying's historical volatility. The HV period is configurable from 5 to 250 days, default 30.
OpenD, broker and market-data permissions apply. No universal free price is stated. API reference
An existing broker workflow that needs contract volatility history. One platform family, not two feeds.
For BTC and ETH, choose the venue first
CME bitcoin and ether options and offshore books such as Deribit are different markets, with different providers. FlashAlpha covers the CME side. On Growth, /v1/volatility/BTC=F returns the same IV/RV spreads as for a US stock, with GEX on the same key, and ETH=F and the micro contracts MBT=F and MET=F work the same way. At 09:23 UTC on November 12, 2026, BTC=F showed ATM IV of 35.45 against 30-session RV of 30.12, a spread of 5.33 points.
For offshore venues, six crypto providers bring the total to seventeen, and Kaiko is listed as a migration candidate. Check the venue, 24/7 annualization, sampling interval and tenor before you compare them.
Crypto VRP providers and API access.
Provider
Documented measure
Access and limits
CryptoDataAPI
DVOL and realized volatility with an explicit IV − RV.
Current BTC IV/VRP free with a key. ETH on Pro at $29/month. History and term structure on Pro Plus at $99/month. Official docs
CryptoGamma
BTC and ETH snapshots include IV, RV and volPremium. The formula and realized windows require confirmation.
Free token through sign-in. Quotas, methodology and publication rights require confirmation. API docs
CayøLargo
ATM IV against RV7, RV30 and RV90. The IV schema uses tenor buckets.
The central RV30 premium is on Pro. Reviewed Pro price: $24,000 annually, $2,000/month equivalent. B2B with KYB and tiered sampling. Surface docs; pricing
CryptoDataDownload
ATM IV30 against RV30 with four realized estimators, as a daily dataset.
Full API $79.99/month. The free CSV and cheaper web or download access are different products. Data catalog
DripMetrics AI
BTC ATM IV² − annualized RV², with short RV windows from 30 minutes to 3 hours.
Paid x402 per request. The exact options-route price requires confirmation. This is not a 30-day IV − RV spread. Product and formula
Madjik
M10028: BTC DVOL − 30-day annualized RV from hourly prices, at daily cadence.
Starter $29/month with a limited trial. Variant and window metadata require confirmation. "Public" does not mean a free API. Metric; pricing
Kaiko / former Amberdata
Institutional volatility analytics. The current VRP endpoint requires confirmation with Kaiko.
Kaiko confirms the integration took effect November 1, 2026. Ask Kaiko for the current VRP endpoint and commercial package before you integrate. Migration notice
A minute-based squared-variance measure cannot be ranked against a daily DVOL-minus-RV30 series.
Four different numbers share the VRP label
Two providers can both be right and still disagree, because "VRP" names at least four calculations.
Measures that appear under a VRP label.
Measure
Calculation
What it tells you
Trailing volatility spread
Current IV − past realized volatility
How today's implied level compares with recent movement. Future risk is still unknown.
Forecast premium
Current implied quantity − a model's expected future realized quantity
A model-dependent estimate. The forecast needs its own evaluation.
Forward realized difference
IV observed at the start − the RV that followed
An outcome. It is only known after the realized window finishes.
Variance difference
IV² − RV²
Squared volatility units, more sensitive to large moves. Not the same number as IV − RV.
Most providers here return the trailing spread in volatility points. DripMetrics returns the variance difference and Unusual Whales the forward outcome. An ATM-IV difference is also not a model-free variance-swap premium.
Even trailing spreads pick their legs differently. Tradytics and ApexVol use constant-maturity IV. Alphanume uses a listed ATM call near 30 calendar days and returns its expiry, strike and days to expiry. Unusual Whales maps 21 trading-day RV to 30 calendar-day IV by default. Tradytics returns vrp from GET /options/volatility, but the reviewed schema does not fully state the numeric scaling, so check it before you subtract (current contract).
Sharpe Two and Skylit use model and event labels. A model probability that IV will exceed future RV is not an observed historical spread, and a Tempest earnings-implied move is separate from its trailing VRP box. Keep each measure in its own column, and record how the provider picks its options or which index it uses. The VRP concept page covers the idea, and the formula guide works through the calculation and its limits.
A backtest can use only what was known at the time
A positive trailing spread can become a negative outcome, and the two are known at different times. Illustrative numbers: current IV is 20%, trailing RV is 15%, and the following period realizes 24%.
Known at the decision time
20 − 15 = +5 vol points. This trailing comparison uses only information already observed, not the later 24% reading.
Known after the outcome completes
20 − 24 = −4 vol points. In variance space: 0.20² − 0.24² = −0.0176. It is a different measurement, available later.
Store six fields with every observation: iv_observed_at, rv_window_start, rv_window_end, available_at, formula and units. Use an observation only when available_at <= decision_time, and apply the same rule to ranks and settlement flags.
Each provider stamps its history differently:
Tradytics: readings are live in regular hours until the close is stored around 16:25 New York, and a past date returns that session's close. Daily history starts in November 2025 and lists the IV and RV legs, not a historical vrp field. Daily history.
Alphanume: rows update about every half hour and settle after the close, so a settled row was not known until then. only_final=true returns settled rows only. Endpoint reference.
Unusual Whales: a window row is dated on the IV observation, but its RV outcome cannot feed a signal before realized_date. The rank uses same-horizon observations completed in the preceding year, and the windows route caps history_days at 365 calendar days, apart from plan history limits. Window contract. Unusual Whales versus FlashAlpha covers the wider product.
FlashAlpha returns trailing IV/RV spreads on Growth and the full VRP endpoint on Alpha. The REST routes are /v1/volatility/{symbol} (Growth and above) and /v1/vrp/{symbol} (Alpha and above), and the MCP server exposes them as get_volatility and get_vrp. Growth includes 2,500 requests a day.
vrp_20d is 40.47 − 39.09 = 1.38 volatility points, and vrp_30d is 40.47 − 36.3 = 4.17. The 5 and 10 session spreads are negative because the stock moved more over the last two weeks than the options imply, which the assessment label summarizes as thin_premium. There is an rv_60d leg but no vrp_60d spread.
Method. RV uses daily-close log returns annualized by √252. The IV comes from a selected listed expiry, so it is not constant-maturity IV30. The response also carries skew profiles and a historical_context block with percentile and z-score references built from prior observations only.
What Alpha adds. The VRP route adds a z-score and percentile, a separate variance_risk_premium, put-side and call-side spreads, a term_vrp ladder and a gex_conditioned block read against the dealer gamma regime. Pay for Alpha only if you need those fields or replay.
Two histories, kept separate. A date on the live VRP route returns persisted snapshots from late March 2026. Historical-host replay recomputes supported fields from archived inputs with the current engine. Snapshot contract; replay reference; methodology.
What is free, and what the paid tiers cost
Three providers offer a free key, and none of them covers US single-stock chains.
Oanor: 690 free keyed calls a month at 2 requests per second, per both the plan page and the machine-readable guide. The playground's ten daily tests are separate. The overview says "no key", but the gateway still requires an x-oanor-key header.
CryptoDataAPI: current BTC IV/VRP is free, with 100 calls a day before email confirmation and 1,000 a day after, at 10 a minute. Free access and rate limits.
CryptoGamma: a free token is advertised, but a reproducible comparison needs its formula and allowance in writing.
Other free surfaces are narrower. Sharpe Two's VRP Central is a browser tool, Optionomics offers selected previous-session MCP tools, ApexVol has a free AAPL terminal and OptionsDataAPI has a free platform assistant. None is unrestricted free REST VRP. FlashAlpha's Free plan covers limited GEX with 5 requests a day, without the volatility or VRP endpoints.
Paid entry points fall into three bands. Under $100: Oanor Starter, Madjik, CryptoDataAPI Pro, OptionsDataAPI, Tradytics, CryptoDataDownload, ApexVol, Unusual Whales and Optionomics. Mid-range: FlashAlpha Growth, Alphanume, Skylit and Sharpe Two. Above that: FlashAlpha Alpha and CayøLargo.
How to choose, by research job
Match the provider to the job, then get the details in writing.
Current US IV/RV on a smaller budget: Tradytics, ApexVol, Optionomics or OptionsDataAPI.
Daily screening across the US universe: Alphanume, for cross-sectional ranks and settled rows.
Volatility plus dealer positioning: FlashAlpha Growth for IV/RV spreads and full-chain GEX, or Alpha for directional and GEX-conditioned VRP with covered replay. Skylit suits personal Heatseeker and Tempest workflows.
History labelled with outcomes: Unusual Whales.
Free exploration: Oanor for index proxies, CryptoDataAPI for current BTC.
BTC or ETH on CME: FlashAlpha Growth, with GEX on the same key.
BTC or ETH on offshore venues: a provider from the crypto table.
Before you subscribe, confirm the endpoint's coverage, both volatility legs, the formula and units, the timing and history revisions, and the real cost: add-ons, commitment, meters and any separate history entitlement. A trial is not a permanent free tier.
API access alone does not grant redistribution rights. Standard FlashAlpha plans cover personal and single-team internal use, including professional research and trading; FlashAlpha does not offer redistribution, public embedding or resale. Alphanume Pro is for one named user, and Skylit requires written permission for business or fund use.
Frequently asked questions
What is the best VRP API?
It depends on the market and the formula. For current US IV/RV at low cost, Tradytics and ApexVol document their formulas clearly, and both cost under $100 a month. For volatility with dealer positioning, FlashAlpha Growth returns IV/RV spreads and full-chain GEX on one plan. For BTC or ETH, FlashAlpha covers CME futures options; for offshore venues such as Deribit, use a crypto provider such as CryptoDataAPI or Madjik.
Is there a free VRP API?
Yes, with limits. Oanor gives 690 keyed calls a month for index and proxy VRP, and CryptoDataAPI gives current BTC IV/RV free with a key. CryptoGamma advertises a free token but does not document its formula. Free dashboards, assistants and trials are not a full free API.
How much does a VRP API cost?
Paid entry points in this guide range from €12.40 a month (Oanor Starter) to $2,000 a month equivalent (CayøLargo Pro). Most US options APIs sit between $69 and $499 a month. FlashAlpha's current IV/RV spreads are on Growth at $299 monthly, and the full VRP endpoint is on Alpha at $1,499 monthly.
Are volatility risk premium and variance risk premium the same?
No. IV minus RV is in volatility units, and IV squared minus RV squared is in variance units. A trailing comparison also differs from a forward-realized outcome or a forecast. Variance versus volatility risk premium explains the difference.
Which VRP API has historical data for backtesting?
Unusual Whales documents window rows with realized-completion dates, up to 365 calendar days per request. Alphanume offers settled daily rows, and Tradytics lists daily IV and RV legs from November 2025. FlashAlpha Alpha includes persisted VRP snapshots from late March 2026 and replay of supported fields from archived inputs.
Is a high VRP a sell signal?
Not by itself. A quiet trailing window can create a large spread shortly before volatility rises. Strategy evidence needs a separate test of timing, structure, costs and risk.
Were all seventeen feeds tested live?
No. This guide reviews first-party documentation and advertised access. It does not certify authenticated availability, calculation accuracy, latency or investment performance.
Sources and ownership
FlashAlpha owns and publishes this guide, and FlashAlpha is one of the providers in it. Research date: November 11, 2026. The links beside each provider go to its own documentation or pricing page. The Tradytics, Unusual Whales, Oanor and ApexVol plan pages were checked November 11, 2026. No feed was benchmarked. The BTC=F reading comes from the live FlashAlpha API on November 12, 2026.
