Mirum's 11% Surge: Private Placement Fuels Rare Disease Expansion Hype

Summary
• Mirum Pharmaceuticals (MIRM) surges 11% intraday, hitting $78.05
• $68.5M private placement announced to fund Bluejay Therapeutics acquisition
• Intraday range spans $70.76 to $78.35, nearing 52-week high of $78.54
• Registration rights agreement filed to enable future resale of private placement shares

Mirum Pharmaceuticals has ignited a sharp rally amid a $68.5 million private placement deal with TCGX, a strategic move to accelerate its acquisition of Bluejay Therapeutics. The stock’s 11% surge reflects investor optimism about expanded pipeline access in viral and liver diseases, despite a -171x P/E ratio signaling speculative momentum. With the 52-week high nearly breached and options volatility spiking, the rare disease sector’s high-risk, high-reward dynamics are on full display.

Private Placement Fuels Acquisition-Driven Optimism
Mirum’s 11% intraday surge stems from its $68.5 million private placement with TCGX, announced alongside its $200 million financing earlier this month. The proceeds will fund clinical development and commercialization post-acquisition of Bluejay Therapeutics, a biotech focused on viral and liver diseases. The registration rights agreement ensures liquidity for private placement shares, while the $68.48 per-share price—below today’s $78.05—creates a valuation premium. Investors are betting on Mirum’s expanded pipeline, including Bluejay’s assets, to unlock synergies in rare disease therapeutics.

Options Playbook: Capitalizing on Volatility and Liquidity
• 200-day MA: $58.01 (well below current price)
• RSI: 43.25 (neutral, suggesting potential for further upside)
• MACD: -0.96 (bearish) vs. Signal Line: -1.08 (bearish), but Histogram: +0.12 (bullish divergence)
• Bollinger Bands: Price at $78.05 near upper band ($74.76), indicating overbought territory
• Key support/resistance: 30D support at $72.05, 200D support at $43.89

Mirum’s technicals suggest a short-term bullish bias, with RSI neutrality and MACD divergence hinting at potential continuation. The 52-week high at $78.54 is a critical psychological level to watch. Two options stand out for aggressive positioning:

• MIRM20260116C80 (Call, $80 strike, Jan 16 2026):
- IV: 46.33% (moderate)
- LVR: 23.64% (high leverage)
- Delta: 0.459 (moderate sensitivity)
- Theta: -0.116 (rapid time decay)
- Gamma: 0.039 (moderate price sensitivity)
- Turnover: $11,985 (liquid)
- Payoff at 5% upside ($82.00): $2.00/share profit
- This contract balances leverage and liquidity, ideal for a 5-6% near-term move.

• MIRM20260417C85 (Call, $85 strike, Apr 17 2026):
- IV: 35.53% (reasonable)
- LVR: 19.26% (moderate leverage)
- Delta: 0.400 (moderate sensitivity)
- Theta: -0.035 (moderate time decay)
- Gamma: 0.024 (lower price sensitivity)
- Turnover: $4,050 (liquid)
- Payoff at 5% upside ($82.00): $0.00/share (break-even)
- Offers longer-term exposure with lower immediate risk, suitable for holding through Bluejay acquisition timelines.

Aggressive bulls should consider MIRM20260116C80 into a test of $78.54, while longer-term holders may favor MIRM20260417C85 for post-acquisition catalysts.

Backtest Mirum Stock Performance
The backtest of MIRM's performance following a 11% intraday surge from 2022 to now shows favorable results. The 3-Day win rate is 51.02%, the 10-Day win rate is 55.69%, and the 30-Day win rate is 59.96%, indicating a higher probability of positive returns in the short term. The maximum return during the backtest was 9.90% over 30 days, suggesting that MIRM can capitalize on intraday gains effectively.

Bullish Setup: Watch 52-Week High and Acquisition Timelines
Mirum’s 11% surge is driven by a well-capitalized acquisition strategy, with technicals and options volatility aligning for a bullish near-term bias. The 52-week high at $78.54 is a critical threshold—breaking it could trigger a re-rating of its rare disease pipeline. While sector leader Johnson & Johnson (JNJ) remains flat at +0.18%, Mirum’s speculative momentum is self-contained. Investors should monitor the $78.54 level and the Q1 2026 Bluejay acquisition timeline. For immediate action, target MIRM20260116C80 if $78.54 is breached, or MIRM20260417C85 for a longer-term play.