Spread axes: entry and exit

A bundle's entry and exit are filled against different sides of the order books, so they have different spread axes. Each axis is one of the two executable spreads that the server measures on a lot (see "Bundle window").

Polarity

Polarity is which leg is short and which is long. The "Arbitrage position polarity:" switch:

Polarity	Legs	Entry axis	Exit axis
"Convergence"	SHORT MAX · LONG MIN	Bid MAX − Ask MIN	Ask MAX − Bid MIN
"Divergence"	LONG MAX · SHORT MIN	Ask MAX − Bid MIN	Bid MAX − Ask MIN

The axis labels on the charts are "Entry · …" and "Exit · …" with the legs' actual tickers. Switching polarity swaps the axes. The window opens in convergence.

• A perp–spot bundle is always in convergence: spot is long-only.
• If the account cannot hold both sides at once, the other polarity is locked until the bundle is flat again: an opposite trade would net off the open position.
• Each polarity has its own levels, positions and exits: an exit closes only the position of its own polarity.

Gross and net

The charts show the gross spread. The server makes decisions on the net spread, taking into account the taker rates of both legs:

• entry net = gross − fees of both legs;
• exit net = gross + fees of both legs.

Both legs are always filled with market orders, at the taker rate. A leg's rate is the exchange's rate or your own from the connection's "Fees" block.