Bull Call Spread

A bull call spread is a defined-risk bullish trade. You buy a call at a lower strike and sell a call at a higher strike, both with the same expiration. You pay a net debit at entry. Max loss is that debit. Max gain is the strike width minus the debit. It costs less than a naked long call but gives up unlimited upside above the short strike.

Traders use it when they expect the stock to rise moderately, not shoot straight through the upper strike.

Structure

Leg	Action	Role
Lower strike (K1)	Buy call	Long delta, pays premium
Higher strike (K2)	Sell call	Reduces cost, caps upside

• Entry: Net debit (long premium minus short premium).
• Max loss: Debit paid × 100 per contract.
• Max profit: (K2 − K1 − debit) × 100 at or above K2 at expiration.
• Breakeven at expiry: K1 + debit per share.

Example width $10, debit $3: max profit $7 per share ($700 per contract), max loss $300.

Worked example

Stock XYZ at $100. You open a bull call spread:

1. Buy the $95 call for $7.00.
2. Sell the $105 call for $4.00.
3. Net debit = $3.00 per share ($300 per contract).

Width = $105 − $95 = $10. Max profit = $10 − $3 = $7 per share ($700). Breakeven ≈ $95 + $3 = $98 at expiration.

If XYZ finishes at $108, the spread is worth $10 intrinsic ($1,000), minus $300 paid = $700 profit.

Payoff at expiration

Rough P/L per contract (before fees):

Stock at expiry	Spread value	P/L
$90	$0	−$300 (max loss)
$98	~$300	~$0 (breakeven)
$100	~$500	~+$200
$110	$1,000	+$700 (max profit)

Between K1 and K2, profit ramps linearly. Above K2, profit is flat.

Greeks for this position

Net delta is positive but smaller than a lone long call. The short upper call subtracts delta. As the stock rises toward K2, delta increases until you are near max profit, then flattens.

• Gamma: Positive in the middle of the range, lower than a single long call. Large moves into the wings change delta more slowly than a naked option.
• Theta: Usually negative overall (you are net long options), but less painful than buying only the lower call. Time decay hurts most when the stock sits between strikes with little intrinsic value.
• Vega: Typically positive (net long volatility). A drop in implied volatility can shrink the spread value before expiration even if the stock is flat.

See Delta explained for how delta signs combine across legs.

When traders consider it

Your view	Bull call spread vs alternatives
Moderately bullish	Prefer spread over long call to cut cost and accept a cap
Very bullish (big move)	Long call may pay more if price blows past the short strike
Mildly bullish, want credit	Look at bull put spread instead

Pair with vertical spreads overview to see the full family.

Risks and management

• Early assignment: The short call can be assigned if deep ITM. Know how your broker handles exercise and whether you want to close before ex-dividend on calls.
• Pin risk: Stock finishing between strikes leaves one leg ITM and one OTM. Plan whether to close or let expire.
• Liquidity: Wide bid-ask on either leg widens effective debit. Trade liquid strikes and expirations.
• Gap risk: Overnight gaps can jump through your profit zone. Max loss stays capped at the debit, but you may not get to exit at mid prices.

Closing before expiration is common when most of max profit is captured or the thesis breaks.

Order entry and fills

Enter both legs as a spread order when your broker supports it. You specify a net debit limit (for example, pay $3.00 or less). Single-leg entries can leave you naked short a call if the long leg fills and the short does not. Check the combo quote against the sum of legs. Penny-wide markets on SPY-style products fill tighter than small-cap names.

Sizing and account impact

Risk per spread is the debit. If you pay $300 per contract, that is the worst-case cash loss at expiration (excluding fees). Many traders risk a fixed percent of account per trade (for example 1–2%) and divide by max loss to get contract count. Bull call spreads use less buying power than stock but more than some credit spreads because you pay upfront.

Common mistakes

• Choosing strikes too narrow so max profit is smaller than commissions.
• Ignoring earnings between entry and expiry (IV and gap risk).
• Holding for max profit when 70–80% of max is available with weeks left (theta accelerates differently on each leg).
• Forgetting the short call is a real obligation if assigned early.

Mark-to-market before expiration

With weeks left, the spread trades like a partial long call. If the stock rallies toward the upper strike, delta increases but gamma fades as you approach max profit. If the stock stalls below the lower strike, theta erodes the debit. A drop in IV hurts both legs but the long lower strike usually has more vega per dollar.

Many traders close at 50–70% of max profit rather than waiting for expiration pin risk on the short call. Check open P/L in the builder against the expiration table so you are not surprised by mid-life drawdowns.

Tax and reporting (high level)

Options tax treatment may depend on holding period, assignment, and whether legs are reported as a single strategy on your 1099-B. Rules vary by account type and country. This is not tax advice; keep records and ask a qualified preparer how your broker reports spread closes.

Try in ThetaViz

Open bull call spread builder to load strikes from a live chain, view breakevens on the chart, and compare net Greeks with the demo above.

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ThetaViz provides educational tools only. This guide is not investment, tax, or legal advice. Prices, margin requirements, and tax rules change. Confirm details with your broker and qualified professionals before trading.