Summary
Spread vs Close compares the current Orderbook spread or midpoint context with the relevant previous closing price.
How to read it
Use it to see whether the current visible trading range is positioned above or below the prior close. Read it together with the Best Bid, Best Offer, and the date of the close used for comparison.
Things to keep in mind
The value can move quickly and may be unavailable when one side of the Orderbook is missing. It is a market snapshot, not a measure of realised return.