SPX price backup
If the SPX quote stops updating during the regular session, the backup uses a fresh SPY price and the last verified relationship between the two. That relationship stays fixed until direct SPX updates return. SPY-based chart candles are labeled as an estimate.
TLT and ZB
View TLT options levels mapped to ZB prices in the Index workspaces. These are TLT-derived references, not native ZB options exposure. Converted levels appear once a valid price relationship is available.