Interactive Brokers increasing margin thresholds

Interactive Brokers is the best accessible brokerage with respect to margin. They are also exceedingly inexpensive (for Canadian currency, their rates are currently 2.5% between $0 and $100k, 2.0% for $100k-$1M, and 1.5% above that). I have not employed margin for quite some time, but others can borrow money at low rates. Considering the prevailing interest rates, others see it suitable to leverage by borrowing very cheap money and investing it into income-yielding securities, while skimming the few percentage points. That said, the securities that are now available to leverage from now has a market cap limitation of US$250M or above, as they announced today:

As a result of recent market volatility, please be advised that IB is increasing the margin rates on low capitalization stocks (currently defined as companies with less than $250 million in market capitalization). The margin increases will occur in three steps beginning on Wednesday, September 21, 2011 and ending on Friday, September 23, 2011. The margin rates will increase to 50%, 75% and 100% at the open of business on 9/21/2011, 9/22/2011 and 9/23/2011, respectively.

The current list of stocks which are subject to this margin increase is subject to change. The current list can be found on the following page:

Upon implementation, any of the incremental margin increases may result in a margin deficit in the account. A margin deficit implies that an account becomes subject to automated liquidation. Please carefully review the current positions within your account and adjust the portfolio accordingly.

I suspect the brokerage firm has done some risk analysis on customer profile accounts and has determined that the concentration within these low capitalization stocks has reached a point where they could not spontaneously liquidate the securities at an acceptable price in the event the stock market crashes. In such an event, the brokerage would be left to cover the remaining shortfall in the customer’s account (as presumably the customer will not be cutting a cheque back to cover such a deficit).

Interactive Brokers (Nasdaq: IBKR) is a very well-run operation and they probably did not make this decision lightly as it will be costing them some money.