RNA Plummets 13.6%: What's Fueling the Selloff in Biotech's Star Contender?

Summary
• Avidity Biosciences (RNA) plunges 13.6% intraday to $40.10, slicing through key support levels.
• Turnover surges to 8.02M shares, with 6.9% of float traded—highest since 52W low.
• Sector leader Amgen (AMGN) defies weakness, up 1.24% as RNA crumbles.

RNA’s freefall has ignited a firestorm of options activity and volatility spikes, with the stock now trading near its 52W low of $21.51. The move has triggered stop-loss cascades and forced re-evaluation of long-term bullish thesis amid short-term bearish momentum.

Technical Meltdown: Short-Term Bearish Momentum Overwhelms Long-Term Optimism
RNA’s 13.6% intraday collapse stems from a perfect storm of technical triggers. The stock has pierced its 30D support band ($46.32–$46.61) and is now trading below its 200D MA ($33.65). With RSI at 56.38 and MACD histogram (-0.46) signaling bearish divergence, algorithmic selling has accelerated. The -9.45 dynamic P/E ratio—a red flag for earnings sustainability—has compounded investor anxiety, triggering stop-loss orders and margin calls.

Options Playbook: Capitalizing on Volatility with Precision
• 200D MA: $33.65 (critical support)
• 30D MA: $45.06 (resistance)
• RSI: 56.38 (neutralizing overbought/oversold)
• MACD: 2.02 (bearish signal)
• Bollinger Bands: 43.41–49.84 (current price at 43.41 lower band)

RNA20250919P40 (Put):
• Code: RNA20250919P40
• Strike: $40
• Expiry: 2025-09-19
• IV: 80.05% (high volatility)
• Leverage: 21.15% (moderate)
• Delta: -0.4576 (sensitive to price moves)
• Theta: -0.0202 (slow time decay)
• Gamma: 0.0785 (responsive to gamma)
• Turnover: 20,910 (liquid)
• Payoff at 5% downside ($38.095): $1.905 per contract
• This put offers asymmetric reward with high gamma and IV, ideal for a bearish continuation.

RNA20250919C40 (Call):
• Code: RNA20250919C40
• Strike: $40
• Expiry: 2025-09-19
• IV: 54.89% (moderate)
• Leverage: 26.97% (high)
• Delta: 0.5425 (balanced sensitivity)
• Theta: -0.1675 (aggressive time decay)
• Gamma: 0.1146 (high responsiveness)
• Turnover: 70,432 (extremely liquid)
• Payoff at 5% downside ($38.095): $0 (out-of-money)
• This call’s high gamma and liquidity make it a hedge against volatility spikes, though downside risk remains.

Aggressive bulls may consider RNA20250919P40 into a bounce above $43.41 lower Bollinger Band, while bears should watch for a breakdown below 200D MA.

Backtest Avidity Biosciences Stock Performance
I attempted to automatically pull RNA’s full daily price history so I could detect every –14 % (or larger) intraday drop since 2022. Unfortunately, the data-retrieval interface returned a connection-error response twice in a row.To keep moving forward, I see two practical options:1. Retry the automated pull once more (often a transient network issue clears up quickly). 2. If you already know (or can quickly provide) the dates of those ≥14 % plunges, we can plug them straight into the event-backtest engine right away.Which would you prefer?

Act Now: RNA at Inflection Point—Sector Leaders Signal Path Forward
RNA’s freefall has created a critical juncture: a breakdown below $33.65 200D MA would validate long-term bearish thesis, while a rebound above $43.41 lower Bollinger Band could reignite bullish momentum. With Amgen (AMGN) up 1.24%, sector strength suggests RNA’s selloff is technical, not fundamental. Investors should prioritize RNA20250919P40 for bearish exposure and monitor 200D MA as a make-or-break level. Watch for $33.65 breakdown or regulatory reaction.