Quote from jimrockford:
I think IB is one of the safest companies at which to trade futures. The safest way to do it is to hold all of your cash in T-Bills in your IB securities account. If you then trade futures, IB extends a margin loan of up to 97% of the value of your T-bills, and transfers that margin loan to your IB futures account. If IB went bankrupt, this arrangement would make it impossible for IB to sieze your property legally in order to cover futures trading losses incurred by other customers, which is normally a serious risk when you trade futures at any broker. Another benefit of IB's T-bills technique is that the ENTIRE AMOUNT of your T-bills will be fully covered by $500,000 of SIPC insurance at ALL times
Jimrockford, I fully agree with most of your comments regarding the credit risk associated with accounts at FCM's. It was amazing during the Refco debacle to realize how many people who believed that they had no exposure because their margin at Refco was held in Tbills.
However, your comment, quoted above, regarding the reduction in credit exposure from using IB was incomplete in an important respect and could be misleading as a result.
I agree that IB's structure reduces the amount of credit exposure as compared to most futures accounts. However, this reduction may be *very small* for many people depending on the positions in the account.
In order to illustrate, I will use the terms "required futures margin" to mean the amount which required to be held in your futures account to support your futures positions, and "excess margin" to mean the amount which is surplus and could be withdrawn from your account. Few people are willing to transfer funds in and out of their futures account daily, so most people maintain some excess margin in their futures account.
At most futures brokers, this distinction is unimportant since both of these amounts are held in your futures account (either in cash or bills) and are then subject to the segregated funds regime and credit risk you described earlier. In a bankruptcy caused by a customer loss, the entire amount would be subject to a prorata credit loss.
At IB, by contrast, their computer system *automatically* transfers amounts in and out so that *only* the required futures margin is held in the futures account. It is important to recognize that the required futures margin is subject to credit risk in the same manner as with any other futures broker.
The benefit of the IB structure is that without any work by the customer, the "excess margin" is always held in the securities account and is covered by SIPC. A customer who has no excess margin will experience *no* reduction in credit exposure.
Suppose, for example, that you have 500k in tbills and have 400k of required futures margin. (At IB this would be in a securities account with 500k bills and a 400k margin loan, and a futures account with 400k in cash.) Suppose further that your futures broker (IB or some other broker) is bankrupt as a result of a giant customer loss.
At a typical broker, you would lose some portion of the 500k prorata with other customers. At IB you would lose some prorata portion of 400k. At IB, the 100k of equity in your securities account would be fully protected by SIPC. If the recovery rate were 0%, customers at IB would lose only 400k while those elsewhere would lose 500k.
After reading your comment I couldn't tell whether you understood that you would lose 400k in this example, or whether you were under the impression that you would somehow lose nothing.
One further note: although IB's structure reduces credit risk, it provides significantly less economic benefit from using tbills than does a typical futures account. In my example above, the trader is incurring the negative spread between the interest rate on the bills and the margin loan at IB. The trader should eliminate this by selling 400k of the bills. At most futures brokers, there wouldn't be any negative spread since the bills would directly be used as margin.