If I have a cash account with $10K (just an easy example amount) and I daytrade options spreads (e.g. verticals), how does each such trade affect the buying power?
For example, buy XYZ vertical for $100, then sell the same vertical for $110. Both transactions are not settled until tomorrow - that part I know. But what happens to the buying power?
Does it get reduced by the initial $100 debit?
Or, does it get reduced by the cost of the long leg (e.g. $500)?