OptionsHouse - how to calculate stock buying power + max allowed portfolio value

[VegasWhiz]

Is anyone here facing issues with how optionshouse calculates stock buying power and max allowed portfolio value ? Per optionshouse faq section, margin requirements are as follows:

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The maintenance margin requirement for long stock above $5 is based on a comparison of the stock position’s value to the absolute value of all marginable stocks in the account. This includes long and short stock.
Stock position less than 25% of absolute value of portfolio: 25%
Stock position 25-35% of absolute value of portfolio: 30%
Stock position 35% or more of absolute value of portfolio: 40%
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Let’s assume all my positions are long stocks above $5 and each stock position is less than 25% of my total portfolio. In this scenario, if I have $100K in my account, I should be able to have a portfolio value of upto $400k if I were to take full advantage of maintenance margin requirements. That is, 4 times the cash in my account. But, I noticed that I’m only able to get upto around 3.17%. Anyone else noticed this ?

Any help to demystify Optionhouse’s calculations in this regard would be really appreciated.

 

[spd]

I havent funded my OptionsHouse account yet, but the demo margin does seem a little wonky. I havent sat down and done the math yet though.

 

[blobmorse]

I don't know about Optionhouse, but our clients that we introduce to Penson Financial are subject to the OCC calculator.

http://www.theocc.com/risk-management/cpm/