Box spreads can be dangerous if you don’t know what you are doing. Make sure you’re using European-style options (which may only be exercised at expiry) to avoid the risk of early assignment breaking your box. If you lose one of the short options, it’s no longer completely market-neutral and you’re exposed to delta risk.
You also need to open the entire spread at once instead of “legging in”, or you can lose money to slippage.
And in a margin account, a broker can typically sell any of your positions (because they’re collateral) to protect its interests, even part of a spread, which can again expose you to delta risk if they don’t close your whole box at once. And a broker can typically increase their margin requirements during times of market volatility. They’ll usually give you the courtesy of a margin call to give you the time to put up funds or liquidate assets in your preferred priority, but again, in a fast-moving market they are not required to wait for you to protect their interests. You have to watch these, and I can’t call them risk-free.
And in a margin account, a broker can typically sell any of your positions (because they’re collateral) to protect its interests, even part of a spread, which can again expose you to delta risk if they don’t close your whole box at once.
I guess technically it’s actually “expose you to gamma risk” because the broker would only close one of your positions if doing so reduced margin requirements / increased buying power, and assuming you’re overall long the broad market, that can only happen if doing so decreases overall delta risk. Another way to think about it is that as far as delta risk, it’s the same whether they sell one of your options that long the SPX or sell one of your index ETFs. Hopefully they’ll be smart enough to sell your index ETFs because that’s much more liquid?
The above is purely theoretical though. Has this actually happened to you, or do you know a case of it actually happening?
I guess technically it’s actually “expose you to gamma risk”
Yeah, that sounds right. But gammas can turn into delta as the market moves. If you do box with American options and get assigned early, the shares (or short shares) will hedge you for a while because they’ll have a similar contribution to your overall portfolio delta as the option they replaced, but it’s not going to have the same behavior as an option when the price moves. So you’d want to close and reposition before that happens, which, of course, requires capital and commissions.
Hopefully they’ll be smart enough to sell your index ETFs because that’s much more liquid?
You would think. Sometimes you get liquidated by an algorithm though. I’ve heard that Interactive Broker’s liquidation algorithms are especially aggressive, which is part of how they can offer such competitive margin loan rates. (They also have a “liquidate last” feature that lets you protect some positions from the algorithm for longer. Definitely use that for the boxes.)
The above is purely theoretically though.
Yes. I have no first-hand experience with this. I have heard things on forums from people, but I can’t call that a reliable source.
Interactive Broker’s liquidation algorithms are aggressively fast, but my rather limited experience suggests they’re pretty sensible about what to liquidate.
Box spreads can be dangerous if you don’t know what you are doing. Make sure you’re using European-style options (which may only be exercised at expiry) to avoid the risk of early assignment breaking your box. If you lose one of the short options, it’s no longer completely market-neutral and you’re exposed to delta risk.
You also need to open the entire spread at once instead of “legging in”, or you can lose money to slippage.
And in a margin account, a broker can typically sell any of your positions (because they’re collateral) to protect its interests, even part of a spread, which can again expose you to delta risk if they don’t close your whole box at once. And a broker can typically increase their margin requirements during times of market volatility. They’ll usually give you the courtesy of a margin call to give you the time to put up funds or liquidate assets in your preferred priority, but again, in a fast-moving market they are not required to wait for you to protect their interests. You have to watch these, and I can’t call them risk-free.
Good points.
I guess technically it’s actually “expose you to gamma risk” because the broker would only close one of your positions if doing so reduced margin requirements / increased buying power, and assuming you’re overall long the broad market, that can only happen if doing so decreases overall delta risk. Another way to think about it is that as far as delta risk, it’s the same whether they sell one of your options that long the SPX or sell one of your index ETFs. Hopefully they’ll be smart enough to sell your index ETFs because that’s much more liquid?
The above is purely theoretical though. Has this actually happened to you, or do you know a case of it actually happening?
Yeah, that sounds right. But gammas can turn into delta as the market moves. If you do box with American options and get assigned early, the shares (or short shares) will hedge you for a while because they’ll have a similar contribution to your overall portfolio delta as the option they replaced, but it’s not going to have the same behavior as an option when the price moves. So you’d want to close and reposition before that happens, which, of course, requires capital and commissions.
You would think. Sometimes you get liquidated by an algorithm though. I’ve heard that Interactive Broker’s liquidation algorithms are especially aggressive, which is part of how they can offer such competitive margin loan rates. (They also have a “liquidate last” feature that lets you protect some positions from the algorithm for longer. Definitely use that for the boxes.)
Yes. I have no first-hand experience with this. I have heard things on forums from people, but I can’t call that a reliable source.
Interactive Broker’s liquidation algorithms are aggressively fast, but my rather limited experience suggests they’re pretty sensible about what to liquidate.