Janux Therapeutics Plummets 48% Amid Encouraging Trial Data – What’s Fueling the Selloff?

Summary
• Janux Therapeutics (JANX) crashes 47.9% to $17.70, hitting a 52-week low of $16.70
• Positive Phase 1 data for JANX007 in mCRPC reported, with durable responses and manageable safety profile
• Virtual investor event scheduled for 4:30 PM ET to discuss trial updates

Janux Therapeutics’ stock has imploded on Tuesday, plummeting nearly 48% to trade near its 52-week low. Despite the company announcing encouraging Phase 1 clinical data for its prostate cancer candidate JANX007, the selloff has left investors scrambling for answers. The stock’s intraday range—from $18.86 to $16.70—underscores the volatility, with analysts debating whether the move reflects skepticism over data durability or broader biotech sector jitters.

Positive Trial Data Fails to Alleviate Investor Skepticism
Janux’s stock collapse defies the upbeat narrative of its Phase 1 trial results for JANX007, which showed radiographic progression-free survival (rPFS) of 7.9–8.9 months in heavily pre-treated mCRPC patients. While the company highlighted manageable cytokine release syndrome (CRS) and a potential Q2W dosing schedule, investors appear unconvinced by the durability of responses. The 30% RECIST response rate in evaluable patients, coupled with unconfirmed partial responses, has raised questions about the data’s robustness. Additionally, the lack of confirmed responses in the taxane-naïve cohort and the absence of clear pathways to regulatory approval have fueled caution. The virtual investor event at 4:30 PM ET may offer clarity, but the market’s immediate reaction suggests a lack of confidence in the program’s commercial potential.

Options Playbook: Capitalizing on Volatility and Technical Breakouts
• MACD: 1.88 (bullish divergence), Signal Line: 1.33, Histogram: 0.55 (momentum waning)
• RSI: 75.2 (overbought territory, potential reversal)
• Bollinger Bands: $34.94 (upper), $29.59 (middle), $24.24 (lower)—price near lower band
• 200D MA: $26.85 (far below current price)

JANX’s technicals paint a mixed picture. The RSI at 75.2 suggests overbought conditions, while the MACD histogram’s contraction indicates fading bullish momentum. The stock’s proximity to the Bollinger Bands lower boundary ($24.24) hints at a potential rebound, but the 200-day MA at $26.85 remains a distant target. For traders, the key levels to watch are the 52-week low at $16.70 and the 200D MA. A break below $16.70 could trigger a deeper correction, while a rebound above $18.86 might attract short-term buyers.

Top Options Picks:
• JANX20251219C17.5 (Call, $17.5 strike, Dec 19 expiry):
- IV: 98.75% (extreme volatility)
- Delta: 0.567 (moderate sensitivity)
- Theta: -0.061 (rapid time decay)
- Gamma: 0.101 (high sensitivity to price swings)
- Turnover: $59,258 (liquid)
- Leverage Ratio: 10.72% (modest)
- Price Change Ratio: -86.96% (bearish)
This call option is ideal for aggressive bulls expecting a short-term rebound. The high gamma and IV suggest it could benefit from a sharp price move, though theta decay is a risk.

• JANX20251219P17.5 (Put, $17.5 strike, Dec 19 expiry):
- IV: 90.68% (elevated)
- Delta: -0.435 (moderate bearish exposure)
- Theta: -0.0185 (slow decay)
- Gamma: 0.110 (high sensitivity)
- Turnover: $43,455 (liquid)
- Leverage Ratio: 13.61% (attractive)
- Price Change Ratio: +136.36% (bullish)
This put option is a top pick for bearish traders. The high leverage ratio and gamma make it responsive to further declines, while the moderate delta balances risk. A 5% downside to $16.82 would yield a put payoff of $0.68 per contract, offering a 15.7% return on a $4.35 premium.

Action Insight: Aggressive traders may consider JANX20251219P17.5 for a bearish play if the stock breaks below $17.50. For a balanced approach, JANX20251219C17.5 offers upside potential if the virtual event sparks a rebound.

Backtest Janux Therapeutics Stock Performance
Below is the interactive back-test dashboard for the “48 % Intraday-Plunge Rebound” strategy on JANX (2022-01-01 → 2025-12-02). Please scroll the module to view full statistics and individual-trade details.Key takeaways (concise):• Total return: ≈ 119 %; annualised ≈ 50 %. • Risk: max drawdown ≈ 37 %, Sharpe ≈ 0.43 – attractive absolute gains but with elevated volatility. • Trade efficiency: average gain per winning trade ≈ 64 %, average loss ≈ -10 %; win-rate implies edge skewed by a few large rebounds. • The 8 % stop-loss and 10 % take-profit capped downside while letting rebounds run; a 20-day max hold closed positions that drifted sideways.Assumptions & auto-filled parameters:1. Intraday high/low proxy – in absence of tick data, hist30_high / hist30_low were treated as the session’s high/low to detect ≥48 % plunges. 2. Risk controls – defaulted to 8 % SL, 10 % TP and 20-day max hold, common in short-term swing frameworks. 3. Data span – full history available from 2022-01-01 to 2025-12-02 per your request (“2022 to now”). 4. Price type – used close prices for entries/exits (conservative assumption).Feel free to explore the module and let me know if you’d like to adjust thresholds, risk limits, or analyse a different period or ticker.

Critical Crossroads: Will the Investor Event Salvage Janux’s Trajectory?
Janux’s 48% selloff underscores the fragility of biotech valuations in the face of mixed clinical data. While the Phase 1 results for JANX007 are promising, the market’s skepticism highlights the need for clearer pathways to commercialization and regulatory approval. Investors should closely monitor the virtual event at 4:30 PM ET for data that could reignite confidence. In the broader biotech sector, Amgen (AMGN) remains a leader with a 0.51% intraday gain, offering a contrast to Janux’s turmoil. For Janux, a sustained rebound above $18.86 would signal a potential reversal, while a breakdown below $16.70 could trigger further panic. Act now: Position for the event outcome—shorts target $16.70, longs watch for $18.86 retest.