When comparing TradeHus or TradeXYZ with a broker, do not compare a random mark price to a random last trade. Use the perp mid or executable side, then compare it with a broker bid, ask, or reliable reference for the same instrument. For Korean stocks, also think about FX conversion and local market hours. For US stocks, pre-market and post-market quotes can create fake gaps.

A useful spread is one that survives execution checks. The broker hedge must be available, borrow must be known if the hedge is short, and the price feed must be fresh. If the perp is rich but the stock quote is old, the opportunity may be a data artifact. Delta Neutral Monitor labels data age so a user can reject stale comparisons quickly and focus on setups that deserve real manual verification.

Comparison rules

• Match instrument, currency, and trading session.
• Prefer bid/ask or mid over stale last price.
• Check execution size before trusting the gap.