Notable Monday Option Activity: TTD, REPL, UPST

Replimune Group (REPL) logged 6,830 option contracts (~683,000 underlying shares), about 50.6% of its one‑month ADTV (1.3M), led by 2,313 contracts in the $7 put expiring April 17, 2026 (~231,300 shares). Upstart Holdings (UPST) saw 22,484 contracts (~2.25M underlying shares), roughly 48.1% of its one‑month ADTV (4.7M), led by 1,226 contracts in the $50 call expiring January 16, 2026 (~122,600 shares). The flows point to concentrated speculative positioning — a sizable mid‑dated put on REPL and a mid‑dated call on UPST — which could reflect directional bets or hedges ahead of company‑specific catalysts.

Analysis

Market structure: Large single-day options volumes (REPL: 6,830 contracts ≈683k shares ≈50.6% ADV; UPST: 22,484 contracts ≈2.25M shares ≈48.1% ADV) signal concentrated positioning rather than broad sentiment change. Winners in the short term are liquidity providers and directional options buyers; market-makers and delta-hedgers will amplify intraday moves and skew implied volatility. REPL’s heavy $7 put flow implies downside protection demand or aggressive bearish positioning; UPST’s $50 call flow implies speculative bullish or corporate-derivative activity that could pull forward upside expectations.

Risk assessment: Tail risks include a REPL clinical failure or dilutive financing within 3–6 months that would materially gap down the stock, and a macro/regulatory shock that compresses fintech multiples (UPST) across 1–3 months. Immediate (days) risk is IV and delta-hedge-driven volatility; short-term (weeks–months) risk is option expiry and quarterlies; long-term (quarters–years) reverts to fundamentals (trial data, earnings, cash runway). Hidden dependencies: large block trades can be misread—sell-to-open puts can be bullish; gamma-hedging can produce procyclical flows that reverse quickly.

Trade implications: For defined-risk exposure, favor a directional tilt long UPST via a Jan16,2026 $50/$65 call debit spread (limit size to 1–3% portfolio, target 40–60% return, stop 20% loss) and hedge biotech downside by buying REPL Apr17,2026 $7/$4 put spreads (smaller sizing 0.5–1%). Consider a relative pair: long UPST notional vs short REPL equity to neutralize beta; rebalance weekly while IV moves >10%. If IV spikes >20% on REPL, consider selling short-dated covered calls to fund protection.

Contrarian angles: Consensus may misread option volume as directional conviction; verify trade direction (BTO vs STO) via time-and-sales or broker checks—if REPL $7 puts are sold-to-open, that’s bullish. The market often overprices immediate IV after concentrated flow; a disciplined calendar or vertical spread can exploit IV mean reversion if implied vol > historical vol by >50% over 30 days. Historical parallels: concentrated put flow in small biotechs has preceded both accelerated sell-offs and buyout squeezes; position small and let catalysts (trial readout, earnings) resolve outcomes rather than overleveraging.

Key Decisions for Investors

• Establish a 1–3% portfolio long position in UPST via a Jan 16, 2026 $50/$65 call debit spread (defined risk). Target +40–60% profit, trim half at +30%, stop at -20% of premium. Rationale: captures call-flow momentum with capped downside and 11-month theta profile.
• Initiate a defensive 0.5–1% position in REPL by buying Apr 17, 2026 $7/$4 put spreads (or equivalent synthetic protection). If IV on REPL >30% above its 90-day historical vol, size closer to 0.5%; if below, up to 1%. Exit or roll if a financing announcement occurs within 90 days.
• Implement a pair trade: go long UPST notional $1 for every $0.5 short REPL (equity short) to express fintech vs biotech relative preference. Rebalance weekly; close if pair P/L moves >15% adverse or after 3 months if no catalyst.
• Monitor five triggers before increasing size: (1) REPL corporate financing/clinical readout within 90 days, (2) UPST next earnings or regulatory news within 60 days, (3) a move in implied vol >+20% vs 30-day, (4) option flow indicating sell-to-open vs buy-to-open, (5) IV/HV divergence >50%. Take action (scale up/down 50%) when any trigger confirms.