To keep quotes reliable, contracts with open interest below 100 or a bid-ask spread above 50% are treated as bad quotes and excluded. These two rules aren't adjustable.

Annualized yield = premium ÷ breakeven × 365 ÷ days, using the bid (the most conservative fill). Breakeven = strike − premium.

Excess over T-bills = annualized yield − the 1-month US Treasury bill yield. The cash backing the put could have earned that interest anyway; what's left is your pay for taking the downside risk.

Liquidity: more open interest and a tighter bid-ask spread make it easier to fill and close near the quote. Spreads above 25% are flagged in amber.

Realized volatility is computed in-house with earnings days removed. IV above realized vol means you're selling richer than the stock has actually moved. A term kink (this expiry's IV well above the next) usually signals an event before expiry.

Market cap = SEC cover-page shares × close. P/E and net margin are GAAP TTM; free cash flow = operating cash flow − all capex.