I-Mab Plummets 20% in Volatile Session: What's Fueling the Selloff?

Summary
• I-Mab (IMAB) trades at $3.665, down 20.33% from $4.60 previous close
• Intraday range spans $3.20 low to $4.2675 high
• Turnover surges to 3.75 million shares (5.91% turnover rate)
• Technicals show RSI at 55.15, MACD histogram negative at -0.107
Today's dramatic selloff in I-Mab has sent shockwaves through the biotech sector. With the stock trading near its 52-week low of $0.595, investors are scrambling to decipher the catalyst behind this sharp reversal. The $1.00 drop from morning highs to current levels raises urgent questions about liquidity, technical triggers, and potential catalysts in the absence of company-specific news.

Technical Downtrend Amplified by Liquidity Gaps
The 20.33% intraday decline in I-Mab appears driven by a combination of technical exhaustion and liquidity crunch. The stock has pierced below its 30-day moving average of $4.016 and is now trading near the lower Bollinger Band at $3.811. With RSI at 55.15 and MACD histogram negative (-0.107), the short-term momentum has clearly shifted bearish. The absence of company news or sector-specific catalysts suggests this is a classic technical breakdown, exacerbated by the 5.91% turnover rate indicating significant institutional unloading.

Biotech Sector Steadies as Amgen Holds -1.34%
Bearish Playbook: Leveraging the Put Premium in I-Mab
• 200-day average: $1.651 (far below) • RSI: 55.15 (neutral) • MACD: 0.315 (bearish crossover) • Bollinger Bands: 3.811 (lower) • 30D Support: 4.2056–4.2752

Key levels to monitor include the 30-day support zone (4.2056–4.2752) and the critical 200-day average of $1.651. With RSI hovering near neutral territory and MACD signaling bearish momentum, this appears to be a continuation pattern rather than a reversal. The lone put option IMAB20260417P2.5 stands out with 748% leverage and 27.15% implied volatility. While its delta of -0.016 suggests limited directional sensitivity, the high leverage ratio could amplify gains if the stock breaks below $3.20. A 5% downside scenario (to $3.48) would yield a put payoff of $0.98 per share. This contract's theta of -0.000061 indicates minimal time decay, making it suitable for a longer-term bearish position. Aggressive traders may consider this put as a high-leverage play into the next earnings report or FDA decision, but must balance the risk of a rebound above the 30-day MA at $4.016.

Backtest I-Mab Stock Performance
Below is the completed event-backtest for “IMAB -20 % intraday plunge” between 2022-01-01 and 2025-09-10. Key assumptions and notes:1. Event definition • Due to the absence of full tick data, an intraday plunge was approximated as (Low ÷ High – 1) ≤ -0.20 for any trading day. 2. Data source & period • Daily OHLC data were pulled for IMAB.O from 2022-01-01 to 2025-09-10. 3. Detected events • 4 qualifying plunges were found (2022-05-31, 2022-06-13, 2024-08-19, 2025-06-27). 4. Post-event behaviour (30-day window) • Win-rate gradually improved from 50 % on Day-1 to 75 % by Day-24 and beyond. • Average cumulative return at Day-30 ≈ +13.65 %. • No result reached statistical significance at the 5 % level, reflecting the very small sample size.For a full interactive breakdown (daily curves, cumulative P&L, win-rate heatmap, etc.), please open the module below.Feel free to explore the module and let me know if you’d like additional windows (e.g., 60-day follow-through, alternate plunge thresholds, or comparison vs peers).

Critical Support Levels to Watch Before Next Earnings
The sustainability of this selloff hinges on I-Mab's ability to hold above the 30-day support zone (4.2056–4.2752) and the 200-day average of $1.651. With Amgen (AMGN) down -1.34% as sector leader, biotech investors should remain cautious about broader market sentiment. Immediate action items include monitoring the 3.20 intraday low for a potential breakdown and watching for volume spikes that could signal institutional accumulation. For those seeking directional exposure, the IMAB20260417P2.5 put offers a high-leverage vehicle, but only if the stock remains below $3.811 (lower Bollinger Band). Position sizing must reflect the 748% leverage ratio's inherent volatility.