Reading Them HereHow reliable is each figure?

Greeks on this platform are solved from each contract's last traded price, because our data plan carries no live bid/ask. That has consequences worth knowing, and guards worth explaining.

Where you see it: The stale-mark flags and blank values you will occasionally see.

Greeks are not published by exchanges; they are computed. Every value comes from a pricing model fed the contract's current price, and that price is where the honesty is required.

Our options data comes from the SIP consolidated feed across all sixteen US exchanges. What our plan does not include is tick-level quotes, so there is no live bid/ask on an options contract. The mark used instead is the contract's last trade of the session, falling back to the session's volume-weighted average and then the previous close.

Because implied volatility is solved from that mark, and every Greek is computed from that implied volatility, a stale mark produces stale Greeks. On a liquid contract that trades constantly this is a non-issue. On an illiquid strike that last traded hours ago, the Greeks describe the stock as it was at that trade.

A stale-mark flag next to a value means that contract has not traded today, so its figures describe the previous session. The number is shown rather than hidden, with the caveat attached.

A blank value — an em dash — means the contract could not be priced at all. It is deliberately never shown as zero: a theta of $0 would read as "this earns nothing" and a delta of 0 as "no assignment risk", and both are claims we would be making without evidence.

When a position's Greeks cannot be solved, the book-level totals say so — "4 of 6 legs priced" — rather than presenting a partial sum as though it were complete.

For the liquid, high-open-interest names a wheel tends to use, marks are current and the Greeks are dependable in real time. The caveats bite hardest on thin strikes and distant expiries, which are also the contracts a premium seller has the least reason to trade.

Two automated guards sit in front of implied volatility before it is published. One catches readings distorted by a stale mark against a moved stock, detectable by the near-the-money put/call IV ratio blowing out. The other catches readings that are simply impossible for that symbol, measured against its own history. A suppressed reading blanks the IV rather than substituting an older one — swapping a number known to be wrong for a stale one nobody checked is not an improvement.

Like everything in this guide, these are descriptions of conditions and reference levels — context for your own decisions, not instructions to trade.