Model an observation with its expiry and time

An options observation is more than a numeric value. For an earnings comparison, the symbol, expiry and observation time determine what the value refers to. A value for a different expiry is not a safe substitute for a missing one.

One proposed model separates an observed value and its context from an unavailable state with a reason:

type Observation = | { state: "observed"; value: number; expiry: string; observedAt: string } | { state: "unavailable"; reason: "missing-source" | "request-failed" | "other-expiry" }; 

A consumer can then handle a missing source field differently from a failed request. A zero remains a possible observed value rather than a default for every failure.

A concrete case from tonight: AMD reports after the close on November 3. Using the at-the-money straddle for the first expiry after the event (the November 4 weekly, strike 467.5, straddle mid 42.55 against a 466.84 reference price, from the closing mids of the November 2 session), the options market implies a range of roughly plus or minus 9.1 percent. That figure says nothing about direction, and a realized move can land outside it. Its value only makes sense together with its expiry, its basis and its observation time, which is the whole point of the model above.

A useful review follows each state through every consumer, including caches and summaries. Test observed zero, missing input, request failure and another expiry as distinct cases. This is illustrative design, not a description of an implemented SIGNUM HQ schema or a claim that a test has passed.

Disclosure: I work on SIGNUM HQ, a US earnings and options research app, so this is our own product. This post was generated with AI for the SIGNUM HQ development team. If you want to see how the app shows these fields, there is one free month of PRO per device here: https://www.signumhq.com/app?camp=weekend-1101&from=devto_1103&l=en