Building Market Assumptions
ES: Construir Supuestos de Mercado PT: Construir Premissas de Mercado
How to turn a vague intuition about an asset into a concrete assumption that translates directly into an options structure.
From opinion to tradeable assumption
"I think it will go up" is not a tradeable assumption: it is an intuition without edges. A complete market assumption has four components that let you pick structure and strikes unambiguously. Direction — bullish, bearish or neutral. Magnitude — how much, expressed as a range or in standard deviations. Timeframe — over what window. And confidence — how much capital that opinion deserves. The advantage of this discipline is twofold: it forces you to make explicit what is often not fully thought through, and it later lets you evaluate accuracy separately on each dimension, which is the only way to learn from a trade log.
The dimension almost everyone forgets: volatility
To the four components above you must add one that decides whether the trade wins or loses regardless of whether direction was right: the assumption about implied volatility. You can believe a stock will rise 5% in three weeks and simultaneously think its implied volatility is inflated. That pair of beliefs points to one very specific structure — a bull put spread, which profits from both the rise and the volatility compression — and rules out another — buying calls, which would win on direction but lose on vega. Formulating the volatility assumption explicitly, anchored in IV Rank, is what prevents the most frustrating outcome in options trading: nailing the move and losing money.
Where assumptions come from
Four sources, and the sensible approach is to cross them. Fundamental analysis gives structural direction and levels with economic meaning. Technical analysis gives operational levels, regime and range context. The event calendar — earnings, macro data, central bank decisions, options expirations — gives the timeframe and warns where binary risk sits. And volatility metrics — IV Rank, term structure, skew — give the assumption about premium. An assumption resting on a single source is fragile; one where all four point the same way is rare, and that is why it deserves more capital when it appears.
How it translates into a structure
Translation is nearly mechanical once the assumption is formulated. Bullish with expensive volatility: bull put spread. Bullish with cheap volatility: bull call spread or long call. Neutral with expensive volatility: iron condor or short strangle. Neutral with cheap volatility: calendar spread. Large move of unknown direction with cheap volatility: long straddle or strangle. Bearish with expensive volatility: bear call spread. The assumption’s magnitude sets strike distance; the timeframe sets the expiration; the confidence sets the number of contracts. When the assumption is well formed, the structure is not chosen — it is deduced.
Checking the assumption against the market
Before executing, one final check discards a considerable share of bad trades: compare your assumption with the expected move the market itself is pricing, computed as Price × IV × √(DTE/365). If you believe a stock will rise 3% in thirty days and the market prices a one-standard-deviation move of 8%, your assumption is less ambitious than consensus and premium-selling structures fit better. If you believe it will rise 15% and the market prices 8%, you are betting against consensus and should have a specific reason for doing so. This comparison turns an isolated opinion into a relative position against what is already in the price, which is the only thing capable of generating an edge.