Quote from mwerbe:
Is mark to market why my cash balance went negative after my KCI stock leg of the EFP spiked higher. Would I actually pay margin interest on that money if I kept a negative balance.
I believe so. I believe you will make the market rate of interest, but you will also pay IB's margin rate, so that you will pay a net annualized interest rate of roughly 1.5% on the amount of any margin debt extended to you by IB.
You would solve the problem by re-adjusting, by trading out of some EFPs and into others, so that your account will carry no margin debt. You shouldn't do this until the excess margin interest you expect to pay becomes big enough to cover the commission and spread costs you will incur as a result of the adjustments. If, for example, your EFP expires in one month, your negative settled cash would have to be about $857, on the average day, before the net margin interest you paid would amount even to just one dollar.
Note that if you enter an EFP, and then the stock soars, as in the case of KCI, the spread between the SSF and the stock widens, and you suffer a temporary loss on the position. This entire premium, including temporary loss, will decay to zero by expiry.
The fact that in addition to this temporary loss, you may have to pay margin interest, when the stocks in your EFPs soar in value, means that volatile stocks are not the best candidates for an EFP designed to earn interest on unused cash. The risk that this will occur is more than counterbalanced by the possibility that a stock will plummet rapidly after you establish your EFP. If this happens, then you will experience a sudden drop in the amount of the SSF premium, which means an immediate gain to you. It also means that you will now have additional free cash you can put to work in another EFP earning additinoal interest, because that cash is no longer needed to margin the stock position since it has declined in value.
Yes, the risk of a stock soaring does exist, but the risks are very small, and in the long run, they are more than outweighed by the possible gain of a stock plummeting. Recall that stocks decline less often than they rise, but that this is counterbalanced by the fact that stocks fall more rapidly than they rise.
If your stocks decline in value, then adjusting by adding new EFP positions is needed so that you can reduce your positive settled cash balance to zero, thereby making sure that all of your free cash is put to work earning interest. If your positive settled cash balance is an average of $250, on the average day, you will be missing out on about $1 of interest per month, assuming current EFP interest rates of about 5.35%. So again, you don't want to readjust EFPs too often; you want to adjust only when the interest you expect to gain as a result of the adjustment will outweigh the commision and spread costs incurred by making the adjustment.
You need to know how to manage these fluctutations correctly, if you want to obtain maximum benefit from EFPs; but these fluctuation issues are not big enough to detract from the increased return of EFPs.