API Reference

RSI measures momentum on a 0–100 scale, commonly with a window such as 14 periods.

For query parameters, response envelope, expand_underlying, request_id, and pagination (next_url / page), see SMA. Use window for the RSI lookback length.

Endpoint

GET /v1/options/indicators/rsi/{ticker}

Example request

curl \
  "https://api.cutemarkets.com/v1/options/indicators/rsi/O:NFLX260402C00075000/?timespan=day&window=14&limit=10" \
  -H "Authorization: Bearer YOUR_API_KEY"

Sample response

{
  "results": {
    "values": [
      { "timestamp": 1775016000000, "value": 68.48397362973498 },
      { "timestamp": 1774929600000, "value": 66.67445148145187 },
      { "timestamp": 1774843200000, "value": 58.445579575082704 }
    ]
  },
  "status": "OK",
  "request_id": "cm_49c532b5d7ef43209fcf65f6aa74fb42"
}

Interpretation

RSI is bounded between 0 and 100, which makes it easier to compare across contracts than a raw moving average. A high value means recent gains have dominated recent losses inside the lookback window; a low value means recent losses have dominated. For options, the useful question is usually not "is RSI high?" but "is momentum consistent with the contract's spread, volume, expiration, and implied volatility context?"

RSI versus moving averages

RSI compresses momentum into a bounded oscillator. SMA and EMA return price-like values, so they are better for trend levels and crossovers. MACD compares two EMAs and adds a signal line. In a scanner, RSI is best used as one feature beside quote freshness, bid/ask width, open interest, and expiration distance.

curl \
  "https://api.cutemarkets.com/v1/options/chain/NFLX/?expiration_date=2026-04-17&limit=50" \
  -H "Authorization: Bearer YOUR_API_KEY"

Use the chain request to choose a liquid contract first, then request RSI for the selected OCC ticker. That order avoids calculating momentum on a contract that would fail the execution-quality gate.

Practical use in scanners

RSI is most useful after the contract universe has already been filtered. Start with listed expirations, choose candidate contracts from a chain, remove contracts with weak liquidity, then calculate RSI on the surviving OCC tickers. That ordering keeps the scanner from ranking contracts that look mathematically interesting but cannot be traded or audited.

For options, a high RSI can describe strong premium momentum, but premium momentum can come from several sources at once. The underlying may have moved, implied volatility may have expanded, time value may have compressed less than expected, or a sparse print may have moved the series. Pair RSI with quote freshness, bid/ask width, volume, open interest, delta, and expiration distance before using it as a decision feature.

Implementation checks

• Store the window, timespan, series_type, and adjusted flag with every RSI value.
• Confirm the contract has enough bars to support the requested lookback.
• Avoid comparing daily RSI against intraday RSI without a label.
• Reject or flag RSI values from contracts with stale quotes or very wide spreads.
• Review RSI beside the underlying move and implied-volatility context.

These checks make RSI useful as a repeatable feature rather than a chart-only decoration. They also help explain why two contracts with similar RSI values can still have very different risk and execution profiles.