Bull cross and bear cross

Also called Bull cross, bear cross, drift cross

Net call premium moving above net put premium (a bull cross) or below it (a bear cross) by more than 1% of the gross.

On net premium drift, a bull cross is net call premium moving above net put premium, and a bear cross is it moving below.

To ignore chatter around zero, the gap (net call − net put) has to clear a band of 1% of the gross (the sizes of net call and net put added) before a cross counts. The first clear move from the open is a cross; after that, a new cross needs the gap to swing past the band on the other side. Each cross is dated at the minute the gap first turned that way, not the minute it cleared the band.

In Theta Vantage

The triangles on the drift chart mark where each cross began, and Last signal in the strip names the latest with its time. On Pro, a watcher can tell you when drift turns to calls or to puts. A cross describes where premium went, not where price will go.