Merus (MRUS) Soars 36% on $8 Billion Takeover: A Biotech Blockbuster Unfolds?

Summary
• Genmab’s $8 billion all-cash acquisition of Merus triggers a 36% surge in MRUS shares to $93.70
• Merus’ petosemtamab, a Phase 3 bispecific antibody, drives strategic value with two FDA Breakthrough Therapy Designations
• The deal offers a 41% premium over Merus’ closing price, valuing the company at $8 billion

Merus (MRUS) has surged 36% intraday to $93.70, trading near its 52-week high of $94.55. The explosive move follows Genmab’s all-cash acquisition offer of $97 per share, a 41% premium over Merus’ previous close. With petosemtamab’s potential $1 billion+ annual sales by 2029 and Genmab’s deleveraging plans, the stock’s volatility reflects a high-stakes biotech merger. Traders are now parsing technicals and options to capitalize on the momentum.

Genmab's $8 Billion Cash Offer Ignites Merus Shareholder Optimism
Merus’ 36% intraday surge is directly tied to Genmab’s $8 billion all-cash acquisition offer, which values Merus at $97 per share—a 41% premium over its $68.89 close on September 26. The deal, funded by $5.5 billion in debt and cash, accelerates Genmab’s shift to a wholly owned pipeline, adding petosemtamab, a bispecific antibody with two FDA Breakthrough Therapy Designations for head-and-neck cancer. Petosemtamab’s Phase 3 trials, with topline data expected in 2026, and its projected $1 billion+ annual sales by 2029, have galvanized investor sentiment. The transaction’s 80% tender threshold and $416 million regulatory termination fee further reinforce its certainty, driving MRUS to its 52-week high.

Options Playbook: Leveraging MRUS’ Volatility with High-Gamma Contracts
• MACD: 0.84 (bullish divergence from signal line 0.98)
• RSI: 56.05 (neutral, avoiding overbought/oversold extremes)
• Bollinger Bands: Price at $93.70 (above middle band $67.88, near upper band $70.16)
• 200D MA: $50.97 (far below current price, strong bullish trend)

MRUS’ technicals suggest a continuation of its rally toward the $97 acquisition price. Key levels to watch include the 52-week high of $94.55 and the 200D MA at $50.97. The RSI’s neutrality and MACD’s bullish divergence indicate momentum is intact. For options, two contracts stand out:

• MRUS20251017C95 (Call, $95 strike, Oct 17 expiry):
- IV: 8.48% (moderate)
- Delta: 0.27 (moderate sensitivity)
- Theta: -0.0716 (modest time decay)
- Gamma: 0.183 (high sensitivity to price moves)
- Turnover: 117,321 (liquid)
- Leverage Ratio: 312.23% (high)
- Price Change Ratio: -76% (volatility)
- Payoff (5% upside): $3.38 per share (max(0, 98.38 - 95))
- Why: High gamma and leverage amplify gains if MRUS breaks above $95, with liquidity ensuring smooth entry/exit.

• MRUS20251017C90 (Call, $90 strike, Oct 17 expiry):
- IV: 17.70% (elevated)
- Delta: 0.856 (high sensitivity)
- Theta: -0.1907 (rapid time decay)
- Gamma: 0.0599 (moderate sensitivity)
- Turnover: 62,498 (liquid)
- Leverage Ratio: 22.57% (moderate)
- Price Change Ratio: -17% (volatility)
- Payoff (5% upside): $8.38 per share (max(0, 98.38 - 90))
- Why: High delta and leverage offer outsized returns if MRUS surges toward $97, though theta decay requires swift execution.

Trading Hook: Aggressive bulls may consider MRUS20251017C95 for a breakout above $95, while MRUS20251017C90 offers high-reward potential if the stock accelerates toward the $97 offer price.

Backtest Merus Stock Performance
I ran the screen exactly as requested (≥ 36 % single-day jump) and found only one qualifying occurrence (29 Sep 2025). Because the event-backtest engine needs at least two observations to calculate variance-based statistics, it threw the “division-by-zero” error you saw.Two ways to proceed:1. Broaden the filter – e.g. study all ≥ 20 % or ≥ 25 % one-day surges. • This will give us a larger event set and a fully functional statistical back-test. 2. Keep the single 36 % event and do a simple descriptive follow-up manually (e.g. 1-day / 5-day / 20-day returns, max drawdown, etc.) instead of a formal event back-test.Let me know which path you prefer—or if you’d like a different threshold/time-span—and I’ll rerun the analysis.

MRUS at $93.70: A Race to $97 as Acquisition Clock Ticks
Merus’ 36% surge reflects investor confidence in Genmab’s $97-per-share offer, with technicals and options data pointing to a continuation of the rally. The stock’s proximity to its 52-week high and the $97 acquisition price suggests a short-term target near $95–$97. Traders should monitor the 80% tender threshold and Genmab’s deleveraging plans, while the sector leader Amgen (AMGN) rose 0.26% today, underscoring biotech’s resilience. Action: Hold MRUS for the $97 offer or consider the MRUS20251017C95 call for a breakout above $95. Watch for a breakdown below $93.65 (intraday low) to signal waning momentum.