Phio Pharmaceuticals Skyrockets 24.7%—What’s Fueling This Biotech Breakout?

Summary
• Phio Pharmaceuticals (NASDAQ: PHIO) surges 24.7% intraday to $3.13, marking a sharp rebound from its 52-week low of $0.9657.
• The company announces a U.S. manufacturing partnership for its lead compound PH-762 and reports partial responses in Phase 1b trials for skin cancer.
• Intraday volume spikes 965% to 45.68 million shares, the highest turnover rate in its history.

Phio Pharmaceuticals has ignited a dramatic 24.7% rally on July 25, 2025, driven by a pivotal manufacturing agreement and emerging clinical data. The stock’s sharp rebound from its 52-week low highlights renewed investor confidence in its siRNA platform, even as the broader biotech sector remains cautious.

Strategic Manufacturing Pact and Clinical Progress Ignite Bullish Momentum
Phio Pharmaceuticals’ intraday surge is directly tied to two catalysts: (1) a comprehensive drug substance development agreement with a U.S. manufacturer to scale production of PH-762, its lead siRNA compound targeting PD-1 in skin cancers, and (2) updated Phase 1b trial results showing a complete pathologic response in one patient with cutaneous squamous cell carcinoma and a partial response in a Stage 4 Merkel cell carcinoma patient. These developments validate Phio’s non-surgical treatment approach and position PH-762 as a potential blockbuster in the $15 billion skin cancer market, fueling aggressive buying.

Biotech Sector Diverges as Amgen Slides
While Phio Pharmaceuticals’ rally defies the broader sector’s caution, Amgen (AMGN), the sector leader, fell 0.52% intraday, underscoring divergent investor sentiment. The biotech space remains fragmented, with speculative names like PHIO gaining traction on clinical milestones while large-cap peers face profit-taking. This divergence highlights the sector’s dual drivers: near-term clinical progress for small-cap innovators and macroeconomic headwinds for diversified giants.

Technical Bullish Setup and ETF Positioning for Biotech Optimists
• MACD (0.059) crosses above signal line (0.058), confirming a short-term bullish crossover.
• RSI (56.63) remains in neutral territory, avoiding overbought/oversold extremes.
• 200-day moving average ($2.21) acts as a critical support level; a break above $2.463 (200D resistance) could trigger a retest of the 52-week high ($9.79).

Phio’s technicals align with a breakout pattern, supported by a short-term bullish Kline trend and a long-term range-bound structure. The stock is testing its 200-day average as a support, with a projected 10–15% move if it holds above $2.46. However, the absence of a leveraged ETF complicates position sizing, and the lack of active options forces reliance on pure equity exposure. Aggressive bulls may consider a core position with a stop-loss at $2.46, while hedging against volatility with a trailing stop.

Backtest Phio Pharmaceuticals Stock Performance
The backtest of PHIO's performance after an intraday surge of 25% shows poor short-term results, with the 3-Day win rate at 43.59%, the 10-Day win rate at 41.87%, and the 30-Day win rate at 41.11%. The returns over these periods are negative, with a 3-Day return of -0.68%, a 10-Day return of -1.84%, and a 30-Day return of -3.10%. The maximum return during the backtest was -0.11%, which occurred on the first day after the surge, indicating that the ETF tended to underperform in the immediate aftermath of the intraday surge.

Biotech Breakout or Fleeting Rally? Key Levels to Watch
Phio Pharmaceuticals’ 24.7% surge reflects a compelling confluence of clinical progress and manufacturing scalability, but sustainability hinges on its ability to maintain momentum above $2.46. The broader biotech sector, led by Amgen’s 0.52% decline, remains fragmented, creating a favorable environment for speculative outperformers. Investors should monitor the Phase 1b trial’s final cohort enrollment and the stock’s reaction to the 200-day average. A sustained close above $2.73 (intraday high) would signal a shift in sentiment, validating PH-762’s commercial potential. For now, the 52-week low remains a critical floor—break below $2.46, and the rally could unravel.