The run-up to corporate earnings remains one of the most opportunity-rich — and risk‑dense — windows for options traders. One data point that has gained attention recently is intraday and multi‑day rotation in open interest between puts and calls. This piece evaluates whether put–call open‑interest (OI) rotation in the 48–4 hours before an earnings print contains useful predictive information about the direction and magnitude of the post‑earnings gap (the move from prior close to post‑print open), and how traders can translate that signal into pragmatic options trades.

What is OI rotation and why it might matter

“OI rotation” here means directional change in outstanding positions: an increase in put OI alongside shrinking call OI is put‑leaning rotation; the inverse is call‑leaning rotation. The metric most traders can compute quickly is a simple ratio or differential over a fixed window: for example, rotation = (ΔPutOI / PutOI_prev) − (ΔCallOI / CallOI_prev) measured between t=48h and t=4h pre‑earnings.

Why would this correlate with gaps? There are three plausible microstructure channels:

  • Directional positioning build: hedged or directional bets entered ahead of an earnings event (institutional hedges, retail directional plays) change the options demand balance and thus OI.
  • Skew and implied move repricing: concentrated buying of puts or calls alters skew and may signal market consensus on directional risk beyond what IV levels alone capture.
  • Flow as information: options flow often accompanies private information or re‑balancing decisions; persistent rotation can therefore be a proxy for aggregate trader expectations.

Methodology (practical, replicable)

For traders who want to test this hypothesis, a straightforward, transparent approach is:

  1. Universe: large‑cap, liquid single stocks and ETFs where options market depth is sufficient (e.g., S&P 100 components and high‑volume growth names).
  2. Window: measure OI rotation from 48 hours before earnings close to 4 hours before earnings release. Exclude the final 4 hours to avoid confounding with immediate spreads and market‑on‑close activity.
  3. Rotation metric: use percent change in put OI minus percent change in call OI (alternative: log ratio change). Flag events above the 70th percentile for put rotation and below the 30th percentile for call rotation.
  4. Signal test: compare the sign and magnitude of the opening gap after earnings to historical baselines (median absolute gap, volatility‑adjusted gap). Measure directional hit rate and average signed gap when the signal is present versus absent.
  5. Controls: condition on IV percentile, historical earnings surprise magnitude, and recent news flow to isolate pure OI rotation effects.

Why these choices?

The 48–4h window balances time for meaningful position builds against noise from last‑minute order flow and liquidity constraints. Percent‑change metrics normalize across strike liquidity. Percentile flags reduce sensitivity to extreme single events and provide a simple rule for traders to follow.

Empirical observations (summary of results and patterns)

Across a broad cross‑section of liquid names from 2023–mid‑2026, three consistent patterns emerge:

  • Directional tilt over frequency: put‑leaning rotation before earnings tends to increase the probability of a negative opening gap and vice versa for call‑leaning rotation. The effect is not deterministic — it shifts probabilities rather than hitting rates to 90% — but is economically meaningful for risk‑managed trades.
  • Signal strength scales with concentration: rotation concentrated in near‑ATM strikes and in shorter expirations (weekly/monthly) correlates more strongly with gaps than rotation in deep‑OTM options or long‑dated expiries.
  • Interaction with IV: when rotation comes with a rising IV percentile, the predictive value is stronger for magnitude (larger gaps). Pure rotation without IV repricing is more informative for direction than for magnitude.

Traders should note the signal is most robust in names with relatively balanced liquidity (liquid calls and puts) and less reliable in thinly traded single stocks where a single block trade can move OI without changing consensus.

Practical trade implementations

OI rotation is not a free directional arrow; the market often prices anticipated moves into options. Below are implementations that translate the statistical tilt into tradable risk‑reward profiles.

1) Small directional calendar or vertical

Use a modest directional position triggered by rotation: buy a 1–2 delta monthly call (for call rotation) or put (for put rotation) and sell a nearer‑dated calendar or vertical to offset cost. Example: if you buy a 10‑delta call expiring 6–8 weeks out and sell a 7‑to‑14‑day call against it, you capture post‑earnings drift while capping cost and leverage.

2) Earnings gap spread (cashless directional spread)

Enter a tight debit vertical (e.g., 2–3% wide) positioned outside expected IV move but inside where rotation suggests a gap could occur. This limits downside and simplifies assignment risk. Use position size consistent with expected win rate — the OI rotation signal increases win probability but does not guarantee it.

3) Short premium adjustment (when rotation implies small directional edge but high IV)

If put rotation is present but IV is exceptionally high (IV percentile > 90), traders may prefer to sell premium with careful hedges: short a balanced iron condor or a call‑weighted put credit spread, using delta limits to control directional exposure and setting fill‑contingent stop rules through the print.

Execution & risk controls

  • Size conservatively: treat rotation as a tilt, not a conviction. Typical sizing is a small fraction of normal directional exposure (e.g., 1/3 to 1/2).
  • Plan for IV crush and slippage: earnings often compress IV immediately post‑print; use spread structures that survive IV compression or buy premium when justified.
  • Use pre‑defined stop and profit targets: because gaps can be binary, set explicit rules for exit at the open and intraday if the price moves far from initial expectations.
  • Beware of assignment and early exercise around dividend/comp events: keep expiries and strikes in mind to avoid unwanted stock positions.

Case studies (illustrative)

Two illustrative scenarios show how OI rotation might have been used in practice:

  • Large‑cap tech with heavy put OI build in near‑ATM weekly strikes, coupled with rising IV percentile: this setup suggested both a higher probability of a negative gap and larger magnitude. A risk‑controlled approach would be a protective put diagonal (buy longer‑dated put, sell near‑dated put) sized modestly.
  • Consumer retail name with call OI rotation concentrated in deep‑OTM calls but no IV move: this pattern pointed to speculative call buying (low‑conviction) and carried little predictive power; a trader might avoid directional bets and instead sell a small premium spread if liquidity supports it.

Limitations and pitfalls

Several caveats must temper enthusiasm:

  • Correlation ≠ causation: rotation can reflect order flow that is hedging or arbitrage rather than purely directional intent.
  • Data integrity: OI reporting lags and exchange‑level reporting differences can confound measures if not cleaned.
  • Market structure shifts: changes in retail participation, dealer hedging algorithms, or option product launches can alter historical relationships. The 2023–2026 sample shows the signal has evolved; continuous validation is required.
  • Transaction costs and execution risk: multi‑leg spreads executed across thin markets may erase the edge.

Takeaways for options traders

Put–call OI rotation ahead of earnings is a practical, low‑cost signal that tilts the odds on the opening gap. It works best when:

  • Rotation is concentrated in near‑ATM strikes and short expiries;
  • Rotation accompanies IV repricing; and
  • Traders implement disciplined, spread‑based entries with conservative sizing and explicit stop rules.

This is not a silver bullet. Successful use requires clean data, continual retesting across changing market regimes, and careful execution. For traders who integrate rotation into a broader toolkit (IV percentile, options flow, earnings surprises, and fundamental context), it can provide an incremental edge in the noisy arena of earnings‑period options trading.