MIRM Butterfly Strategy

MIRM (Mirum Pharmaceuticals, Inc.), in the Healthcare sector, (Biotechnology industry), listed on NASDAQ.

Mirum Pharmaceuticals, Inc., a biopharmaceutical company, focuses on the development and commercialization of novel therapies for debilitating rare and orphan diseases. The company's lead product candidate is LIVMARLI, an investigational oral drug for the treatment of progressive familial intrahepatic cholestasis disease, as well as for the treatment of Alagille syndrome and biliary atresia disease. It also develops Volixibat drug for treatment of intrahepatic cholestasis of pregnancy and primary sclerosing cholangitis. Mirum Pharmaceuticals, Inc. was incorporated in 2018 and is headquartered in Foster City, California.

MIRM (Mirum Pharmaceuticals, Inc.) trades in the Healthcare sector, specifically Biotechnology, with a market capitalization of approximately $5.48B, a beta of 0.52 versus the broader market, a 52-week range of 42.89-114.99, average daily share volume of 883K, a public-listing history dating back to 2019, approximately 334 full-time employees. These structural characteristics shape how MIRM stock options price implied volatility around earnings windows, capital events, and macro-driven sector rotations.

A beta of 0.52 indicates MIRM has historically moved less than the broader market, dampening realized volatility and producing tighter expected-move bands per unit of dollar exposure.

What is a butterfly on MIRM?

A long call butterfly buys one lower-strike call, sells two ATM calls, and buys one higher-strike call, paying a small net debit for a defined-risk position that maxes out if the underlying pins the middle strike at expiration.

Current MIRM snapshot

As of May 15, 2026, spot at $103.34, ATM IV 44.50%, IV rank 23.05%, expected move 12.76%. The butterfly on MIRM below is built from the same end-of-day chain, with strikes snapped to listed contracts and premiums pulled from the bid/ask midpoint at a 34-day expiry.

Why this butterfly structure on MIRM specifically: MIRM IV at 44.50% is on the cheap side of its 1-year range, which favors premium-buying structures like a MIRM butterfly, with a market-implied 1-standard-deviation move of approximately 12.76% (roughly $13.18 on the underlying). The 34-day window matched to the front-month expiry keeps theta exposure bounded while still capturing the post-snapshot move; longer-dated MIRM expiries trade a higher absolute premium for lower per-day decay. Position sizing on MIRM should anchor to the underlying notional of $103.34 per share and to the trader's directional view on MIRM stock.

MIRM butterfly setup

The MIRM butterfly below is built from the end-of-day chain, with each option leg priced at the bid/ask midpoint of its listed strike. With MIRM near $103.34, the first option leg uses a $100.00 strike; additional legs (when the strategy has them) anchor to spot-relative offsets. Premiums come from the bid/ask midpoint on the listed MIRM chain at a 34-day expiry; the cross-strike IV skew is reflected directly in the per-leg values rather than approximated. Quantity sizing assumes one contract per option leg (or 100 MIRM shares for the stock leg in covered calls and collars).

ActionTypeStrike / BasisPremium (est)
Buy 1Call$100.00$7.85
Sell 2Call$105.00$5.50
Buy 1Call$110.00$3.95

MIRM butterfly risk and reward

Net Premium / Debit
-$80.00
Max Profit (per contract)
$410.28
Max Loss (per contract)
-$80.00
Breakeven(s)
$100.80, $109.21
Risk / Reward Ratio
5.129

Max profit equals the wing width minus net debit times 100 (reached when the underlying pins the middle strike); max loss equals the net debit times 100. Two breakevens at lower-wing plus debit and upper-wing minus debit.

MIRM butterfly payoff curve

Modeled P&L at expiration across a range of underlying prices for the butterfly on MIRM. Each row is one sampled price point from the computed payoff curve; the full curve uses 200 price points internally before being summarized into 10 rows here.

Underlying Price% From SpotP&L at Expiration
$0.01-100.0%-$80.00
$22.86-77.9%-$80.00
$45.71-55.8%-$80.00
$68.55-33.7%-$80.00
$91.40-11.6%-$80.00
$114.25+10.6%-$80.00
$137.10+32.7%-$80.00
$159.95+54.8%-$80.00
$182.79+76.9%-$80.00
$205.64+99.0%-$80.00

When traders use butterfly on MIRM

Butterflies on MIRM are pinning bets - traders use them when they expect MIRM to settle near a specific level at expiration (often the prior close, a round number, or the max-pain strike) and want defined-risk exposure to that outcome.

MIRM thesis for this butterfly

The market-implied 1-standard-deviation range for MIRM extends from approximately $90.16 on the downside to $116.52 on the upside. A MIRM long call butterfly is a pinning play: it pays maximum at the middle strike if MIRM settles there at expiration, with the wing legs capping both the cost and the maximum loss to the net debit. Current MIRM IV rank near 23.05% sits in the lower third of its 1-year distribution, where IV often re-expands toward the mean; this favors premium-buying structures and disadvantages premium-selling structures on MIRM at 44.50%. As a Healthcare name, MIRM options can move on sector-level news flow (peer earnings, regulatory updates, industry-specific macro data) in addition to MIRM-specific events.

MIRM butterfly positions are structurally neutral / pin (limited-risk, limited-reward); the modeled P&L assumes European-style exercise at expiration and ignores early assignment, transaction costs, dividends paid before expiry on the stock leg (when present), and the bid-ask spread on the listed chain. MIRM positions also carry Healthcare sector concentration risk; news flow inside the sector (peer earnings, regulatory shifts, supply-chain headlines) can move MIRM alongside the broader basket even when MIRM-specific fundamentals are unchanged. Always rebuild the position from current MIRM chain quotes before placing a trade.

Frequently asked questions

What is a butterfly on MIRM?
A butterfly on MIRM is the butterfly strategy applied to MIRM (stock). The strategy is structurally neutral / pin (limited-risk, limited-reward): A long call butterfly buys one lower-strike call, sells two ATM calls, and buys one higher-strike call, paying a small net debit for a defined-risk position that maxes out if the underlying pins the middle strike at expiration. With MIRM stock trading near $103.34, the strikes shown on this page are snapped to the nearest listed MIRM chain strike and the premiums come straight from the end-of-day bid/ask midpoint.
How are MIRM butterfly max profit and max loss calculated?
Max profit equals the wing width minus net debit times 100 (reached when the underlying pins the middle strike); max loss equals the net debit times 100. Two breakevens at lower-wing plus debit and upper-wing minus debit. For the MIRM butterfly priced from the end-of-day chain at a 30-day expiry (ATM IV 44.50%), the computed maximum profit is $410.28 per contract and the computed maximum loss is -$80.00 per contract. Live intraday quotes will differ as the chain moves through the trading session.
What is the breakeven for a MIRM butterfly?
The breakeven for the MIRM butterfly priced on this page is roughly $100.80 and $109.21 at expiration, derived from end-of-day chain premiums. Breakeven is the underlying price at which the strategy's P&L crosses zero ignoring transaction costs and assignment risk. The current MIRM market-implied 1-standard-deviation expected move is approximately 12.76%; if the move sits well outside the breakeven distance, the structure's risk-reward becomes correspondingly tighter.
When should you consider a butterfly on MIRM?
Butterflies on MIRM are pinning bets - traders use them when they expect MIRM to settle near a specific level at expiration (often the prior close, a round number, or the max-pain strike) and want defined-risk exposure to that outcome.
How does current MIRM implied volatility affect this butterfly?
MIRM ATM IV is at 44.50% with IV rank near 23.05%, which is on the low end of its 1-year range. Premium-buying structures (long call, long put, debit spreads) are relatively cheap in this regime; premium-selling structures collect less credit per unit risk.

Related MIRM analysis