Let's say taht I operated a bull put spread on at example on AMZN. Lets say that amazon at the moment is at 106. Selling at the money one put (30 days long) at 106 and buying at a lower price one call at 105. What can happen if the price goes under 105? Do i get assigned? What does it mean? That I Need to buy 100 shares of the underlying? I'm asking all this because I'm not understanding how much margin do I need( if I need more because in the worst case i Need to buy at example 100 Shares of Amazon. Or i Just lose the difference in the two prices of the puts? Interactive Brokers talking about margin say this on his sites : Put Spread A long and short position of equal number of puts on the same underlying (and same multiplier) if the long position expires on or after the short position. Margin Initial/RegT End of Day Margin Maximum (Short Put Strike - Long Put Strike, 0) Maintenance Margin Same as Initial Cash or IRA Cash Same as Margin Account (Both options must be European style cash settled) Short Put Strike Price (American style options) IRA Margin Same as Margin Account I wanted to start on Interactive broker, and I have tested on demo accounts the Bull Put Spread and Bear Call Spread. Can someone explain to me, if I'm doing something wrong? How much capital do I need for starting this kind of operation at example on Amazon ? Thank you and sorry for the newbie question. I'm not interested in buying some courses or joining anything, so please be kind.