IDEAYA Biosciences Plummets 12.4%: What's Behind the Sharp Selloff?

Summary
• IDEAYA Biosciences (IDYA) trades at $23.785, down 12.43% from its previous close of $27.16
• Intraday range spans $23.39 to $27.69, reflecting volatile trading
• R&D Day on September 8 highlights positive Phase 2 data for IDE397/Trodelvy combo
• Options volume surges on 22.5-strike puts and 25-strike calls ahead of key catalysts

The stock’s sharp decline follows a volatile session marked by heavy turnover and mixed signals from its options market. While recent clinical data for IDE397/Trodelvy and darovasertib in uveal melanoma generated optimism, the market’s reaction suggests short-term profit-taking or skepticism about execution risks. With the 52-week high at $37.80 and a dynamic PE of -6.96, IDYA’s near-term trajectory hinges on catalysts and technical support levels.

Clinical Optimism vs. Short-Term Profit-Taking
The selloff reflects a mix of post-R&D Day profit-taking and cautious positioning ahead of the September 8 R&D Day presentation. While the company reported a 57% ORR in the IDE397/Trodelvy combination trial for MTAP-deletion urothelial cancer, the market may be pricing in near-term execution risks, such as the need for further data validation or regulatory hurdles. Additionally, the stock’s 52-week low of $13.45 and negative PE ratio (-6.96) highlight structural challenges, though the 57% ORR in the higher-dose cohort (DL2) provides a floor for long-term optimism. The intraday low of $23.39 suggests short-term sellers are testing key support levels.

Options Playbook: Capitalizing on Volatility and Technical Levels
• MACD: 0.697 (bullish), Signal Line: 0.540 (neutral), Histogram: 0.157 (diverging)
• RSI: 73.78 (overbought), Bollinger Bands: 22.77 (lower), 24.69 (middle), 26.61 (upper)
• 200D MA: 21.998 (below current price), 30D MA: 24.58 (resistance)

Key levels to watch: The 200D MA at $21.998 and the 30D MA at $24.58 define critical support/resistance. With RSI at overbought levels and the stock near the lower Bollinger Band, a rebound above $24.69 could trigger short-term buying. Aggressive traders may consider the IDYA20250919P22.5 put option (IV: 56.10%, leverage: 47.04%, delta: -0.309, theta: -0.0086) for downside protection or the IDYA20250919C25 call (IV: 64.43%, leverage: 42.76%, delta: 0.325, theta: -0.0655) for a bullish breakout. The put’s high leverage and moderate delta offer amplified returns if the stock breaks below $22.50, while the call’s theta decay and gamma sensitivity make it ideal for a rebound. Under a 5% downside scenario (targeting $22.60), the put’s payoff would be $0.18 per share, and the call’s payoff would be $0.00 (out of the money).

Aggressive bulls should consider IDYA20250919C25 into a bounce above $24.69. Short-side players may target IDYA20250919P22.5 if the stock breaks below $23.39.

Backtest IDEAYA Biosciences Stock Performance
Below is the event-study back-test you requested. Key assumptions auto-filled by Aime:1. “-12 % intraday plunge” is approximated with a single-day close-to-close drop of ≥ 12 %. (We lack intraday high/low data in the technical feed; please tell me if you prefer a different definition.)2. Analysis window: 2022-01-01 to 2025-09-08 (today).The interactive report is rendered on the right of the chat—open it to explore win-rate curves, cumulative excess returns, and all underlying statistics.Insights snapshot (see module for full details):• Total qualifying events: 3 • 30-day post-event cumulative median excess return: ≈ +28 % (vs. benchmark +3 %). • Positive performance becomes statistically notable after ~30 trading days.Let me know if you’d like to adjust the plunge definition, lengthen/shorten the holding window, or run a comparative study versus peers.

Act Now: Position for R&D Day Catalyst or Short-Term Volatility
The selloff has created a critical inflection point for IDYA, with the 200D MA at $21.998 and the 30D MA at $24.58 defining key battlegrounds. While the 57% ORR in the IDE397/Trodelvy trial provides a long-term floor, near-term volatility hinges on the September 8 R&D Day and execution risks. Sector leader Amgen (AMGN) is down 1.47%, underscoring broader biotech caution. Investors should prioritize the IDYA20250919C25 call for a bullish rebound or the IDYA20250919P22.5 put for downside protection. Watch for a breakdown below $23.39 or a breakout above $24.69 to confirm direction.