Arcturus Therapeutics Plunges 57% on Mixed Phase 2 Trial Data: What Traders Need to Know

Summary
• Arcturus Therapeutics (ARCT) shares nosedived 57% to $9.95, erasing nearly half its value in a single session.
• The stock traded between $9.19 and $10.24, reflecting a volatile intraday range amid investor panic.
• Mixed Phase 2 trial results for ARCT-032, an inhaled mRNA therapy for cystic fibrosis, triggered the selloff.
• The company reported no meaningful improvement in lung function but noted encouraging mucus reduction trends.

Arcturus Therapeutics’ stock has imploded following interim Phase 2 trial data for its flagship cystic fibrosis (CF) candidate, ARCT-032. The 57% intraday drop underscores investor skepticism over the drug’s efficacy despite safety signals. With the stock trading near its 52-week low of $8.04, the market is now scrutinizing the company’s ability to pivot to higher-dose trials and maintain momentum in its mRNA platform.

Mixed Phase 2 Trial Data Sparks Sharp Selloff
Arcturus Therapeutics’ 57% collapse stems from interim Phase 2 results for ARCT-032, an inhaled mRNA therapy targeting Class I cystic fibrosis. While the drug demonstrated safety and mucus reduction in four of six participants, the primary endpoint—improvement in forced expiratory volume (FEV₁)—failed to meet expectations. The lack of measurable lung function gains, despite encouraging CT scan data, has rattled investors. The company’s acknowledgment that observed FEV₁ changes fell within natural variability further amplified concerns. With the trial expanding to a 15 mg dose cohort and a 12-week study planned for 2026, the market is now betting on whether higher dosing can unlock meaningful efficacy.

Biotech Sector Mixed as AMGN Holds Steady
The biotech sector remains fragmented, with Amgen (AMGN) down 0.19% despite Arcturus’ collapse. While ARCT’s selloff reflects trial-specific risks, AMGN’s stability highlights the sector’s resilience in large-cap names. Smaller biotechs with high-risk, high-reward pipelines face heightened volatility, as seen in ARCT’s case. However, the broader sector’s mixed performance suggests that Arcturus’ decline is not indicative of a systemic sell-off but rather a reaction to its unique clinical setbacks.

Options and ETF Strategies for ARCT's Volatile Outlook
• MACD: 0.8306 (bullish divergence), Signal Line: 0.7624, Histogram: 0.0682 (positive momentum)
• RSI: 59.93 (neutral, not overbought/sold)
• Bollinger Bands: Upper $23.34, Middle $20.78, Lower $18.23 (current price near lower band)
• 200D MA: $15.06 (price trading below long-term trend)

ARCT’s technicals suggest a bearish bias, with the stock near its 52-week low and key support levels at $18.02–$18.14. The 200-day moving average at $15.06 could act as a critical floor if the company fails to rally on higher-dose trial optimism. For traders, the focus should be on short-term volatility rather than long-term trends, given the mixed clinical data and upcoming 15 mg cohort enrollment.

Top Options Picks:
1. ARCT20251121P10 (Put Option):
• Strike: $10, Expiry: 2025-11-21
• IV Ratio: 100.98% (high volatility)
• Delta: -0.405 (moderate sensitivity to price drops)
• Theta: -0.0122 (moderate time decay)
• Gamma: 0.1286 (high sensitivity to price movement)
• Turnover: $22,505 (liquid)
• Leverage Ratio: 9.75% (moderate leverage)
• Payoff Estimation: A 5% downside to $9.45 would yield a $0.55 profit per contract.
• Why It Stands Out: This put option offers a balance of high gamma and IV, ideal for capitalizing on near-term volatility if the stock breaks below $10.

2. ARCT20251121C10 (Call Option):
• Strike: $10, Expiry: 2025-11-21
• IV Ratio: 104.98% (high volatility)
• Delta: 0.595 (moderate sensitivity to price gains)
• Theta: -0.0256 (high time decay)
• Gamma: 0.1237 (high sensitivity to price movement)
• Turnover: $73,269 (highly liquid)
• Leverage Ratio: 7.47% (moderate leverage)
• Payoff Estimation: A 5% upside to $10.45 would yield a $0.45 profit per contract.
• Why It Stands Out: This call option is ideal for aggressive bulls betting on a rebound if the 15 mg dose trial sparks renewed optimism. High turnover ensures easy entry/exit.

Trading Outlook: Aggressive traders may consider ARCT20251121P10 for bearish bets or ARCT20251121C10 for a short-term rebound play. Watch for a breakdown below $10 or a rebound above $12.50 to trigger directional moves.

Backtest Arcturus Therapeutics Stock Performance
After exhaustively scanning every ARCT-O trading session from 2022-01-03 through 2025-10-22, no day was found in which the session low was at least 57 % below that day’s open (i.e., low ≤ 0.43 × open). Because the event list is empty, the event-backtest engine could not calculate post-event statistics and therefore returned an error (it requires at least one event date to function). In other words, ARCT has not experienced an intraday draw-down of 57 % or more during the period you specified, so a “post-plunge” performance study cannot be produced.Options going forward:1. Relax the plunge threshold (e.g., −40 % or −30 %) to capture a larger set of extreme-volatility days and evaluate subsequent performance. 2. Extend the historical window earlier than 2022 (e.g., back to 2020) in case such an extreme draw-down occurred before your current start date. 3. Define a different event criterion (e.g., single-day close-to-close declines of ≥30 % or multi-day draw-downs) and back-test those instead.Let me know which approach you’d like to take—or if there is another event definition you’re interested in—and I’ll set up the revised analysis accordingly.

ARCT's Path Forward: Watch for 15 mg Dose Trial Data
Arcturus Therapeutics’ 57% plunge reflects investor skepticism over ARCT-032’s efficacy, but the company’s pivot to a 15 mg dose and 12-week trial in 2026 could reignite hope. Key signals to monitor include the expansion of the Phase 2 cohort and regulatory alignment in H1 2026. For now, the stock remains range-bound near its 52-week low, with options like ARCT20251121P10 offering bearish exposure. Meanwhile, sector leader Amgen (AMGN) remains stable, highlighting the importance of differentiating between trial-specific risks and broader biotech trends. Action Step: Position for volatility with ARCT20251121P10 or watch for a rebound above $12.50 to re-enter long positions.