Argenx Plummets 3.4% Amid Biotech Sector Volatility: What’s Fueling the Selloff?

Summary
• Argenx (ARGX) trades at $848.05, down 3.4% from its previous close of $877.94, with a day range of $827.52 to $853.96.
• Sector-wide regulatory scrutiny and Novo Nordisk’s Alzheimer’s GLP-1 failure weigh on biotech sentiment.
• Options activity surges, with high-volume calls at $840 and $850 strikes.

Argenx’s sharp intraday decline reflects broader biotech sector jitters, driven by regulatory uncertainty and mixed clinical trial outcomes. The stock’s 3.4% drop has drawn attention to its technical indicators and options positioning, as investors weigh short-term risks against long-term bullish trends.

Regulatory Uncertainty and Sector-Wide Jitters Weigh on Argenx
The selloff in Argenx mirrors broader biotech sector turbulence, fueled by the FDA’s recent regulatory reversals and Novo Nordisk’s failed Alzheimer’s trial with semaglutide. These developments have heightened investor caution, particularly in companies with unproven pipelines or regulatory dependencies. Argenx’s own pipeline, while robust, faces indirect pressure as capital flows to more immediate clinical readouts, such as Zealand’s obesity trials. The stock’s technical breakdown below key moving averages (30D: $890.49, 200D: $680.37) has amplified short-term bearish momentum.

Biotech Sector Splits as AMGN Rises, ARGX Falls
While Argenx tumbles, sector leader Amgen (AMGN) rises 2.23%, reflecting divergent investor sentiment. AMGN’s strength stems from its diversified portfolio and recent FDA approvals, contrasting with ARGX’s exposure to regulatory and clinical risks. The biotech sector’s mixed performance underscores a shift in capital toward established players with near-term revenue visibility, leaving smaller innovators like Argenx vulnerable to volatility.

Options Playbook: High-Leverage Calls in a Volatile Biotech Climate
• 200-day average: $680.37 (well below current price)
• RSI: 32.7 (oversold territory)
• MACD: -7.66 (bearish divergence)
• Bollinger Bands: Price near lower band ($880.63), suggesting potential rebound

Argenx’s technicals hint at a short-term oversold condition, but the bearish MACD and declining volume (551,686 shares) suggest caution. For aggressive bulls, the ARGX20251219C840 call (strike: $840, IV: 35.55%, delta: 0.59, theta: -5.42) offers high leverage (47.05%) and liquidity (volume: 250). A 5% downside to $805.65 would yield a $44.35 payoff. The ARGX20251219C850 (strike: $850, IV: 33.74%, delta: 0.48, theta: -4.61) balances risk with moderate gamma (0.0119) and turnover ($122,095). Both contracts benefit from elevated implied volatility and strong gamma, making them ideal for a rebound trade. Aggressive bulls may consider ARGX20251219C840 into a bounce above $840.

Backtest argenx Stock Performance
The backtest of ARGX's performance after an intraday plunge of -3% from 2022 to the present shows favorable short-to-medium-term gains. The 3-Day win rate is 55.60%, the 10-Day win rate is 58.35%, and the 30-Day win rate is 63.85%, indicating a higher probability of positive returns in the immediate aftermath of the plunge. The maximum return during the backtest was 9.07%, which occurred on day 59, suggesting that while there is some volatility, ARGX has the potential to recover and even exceed its pre-plunge levels.

Act Now: Position for Biotech Sector Rebound or Defensive Moves
Argenx’s 3.4% decline has created a short-term oversold condition, but the bearish MACD and regulatory headwinds suggest caution. Investors should monitor the 200D MA ($680.37) as a critical support level and watch for a potential rebound above $840. With sector leader Amgen up 2.23%, biotech investors may pivot to defensive plays or high-conviction options like the ARGX20251219C840. A breakdown below $827.52 could trigger further selling, while a close above $853.96 may signal a reversal. Watch for $840 retest or regulatory clarity.