Earnings Surprise

An earnings surprise occurs when a company's reported earnings per share (EPS) differs from the consensus analyst estimate. A positive surprise (beat) means the company earned more than expected. A negative surprise (miss) means it earned less. Earnings surprises are the single most common cause of large stock gaps and are the reason IV is elevated before every earnings announcement. Options traders live and die by earnings surprises.

Why It Matters

Earnings season creates the most volatile and highest-premium trading environment of each quarter. Roughly 70% of S&P 500 companies beat consensus estimates in a typical quarter, but the magnitude of the surprise and the accompanying revenue and guidance determine the stock's reaction. Understanding how earnings surprises interact with options pricing helps you construct profitable trades around these events.

The key insight for options traders is that the market prices in an expected move via IV before earnings. Your job is to assess whether the actual move will exceed or fall short of this expected move — and position accordingly.

How It Works

How earnings surprises affect stock prices:

• Beat + raise guidance: The most bullish outcome. Stock typically gaps up significantly.
• Beat + maintain guidance: Mildly bullish. Stock may rise modestly or stay flat.
• Beat + lower guidance: Mixed. Stock often falls because guidance matters more than backward-looking earnings.
• Miss + maintain guidance: Mildly bearish. Stock typically falls.
• Miss + lower guidance: The most bearish outcome. Stock gaps down significantly.

The whisper number: Beyond consensus estimates, many stocks have a "whisper number" — the unofficial expectation that sophisticated investors use. A company might beat the consensus estimate but miss the whisper number, causing the stock to fall despite an apparent "beat."

Earnings surprise and IV dynamics:

• IV builds up in the weeks before earnings as uncertainty about the report increases
• The options market prices an expected move based on the ATM straddle price
• After the report, IV crushes — typically dropping 30-60% in the first day
• If the stock moves more than the expected move, straddle buyers profit
• If the stock moves less than the expected move, straddle sellers profit

Post-earnings drift: Research shows that stocks tend to drift in the direction of the earnings surprise for several weeks after the announcement. A stock that gaps up on a big beat tends to continue higher. This "post-earnings announcement drift" (PEAD) can be exploited with directional options trades.

Strategies around earnings surprises:

• Buy straddles: Profit if the actual move exceeds the expected move. Win rate is typically below 50% because IV is priced to encompass the move.
• Sell straddles: Profit if the actual move is less than the expected move. Higher win rate but risk of large loss on a big surprise.
• Calendar spreads: Sell the short-dated high-IV option, keep the longer-dated option
• Directional spreads: Use fundamental analysis to take a directional view and buy a debit spread in the expected direction

Quick Example

Stock STU reports earnings after the close. The stock is at $100. The ATM straddle (weekly expiration) trades for $8.00, implying an expected move of 8%.

Scenario 1 (Sell straddle): The company beats by $0.10 with in-line guidance. The stock opens at $103 (+3%) the next day. IV crushes from 65% to 30%. The straddle drops from $8.00 to $3.50. You profit $4.50 per share selling the straddle.

Scenario 2 (Buy straddle): The company misses badly and lowers guidance. The stock gaps down 15% to $85. IV crushes, but the intrinsic value on the put is $15. The straddle is worth about $15.50. You profit $7.50 per share buying the straddle.

Over many earnings cycles, about 70% of moves are smaller than the expected move (favoring straddle sellers) and 30% are larger (favoring straddle buyers). But the large moves can be very large, making the expected value closer to even for both approaches.