Using Stock Broker Margin to Buy Real Estate

[ether161]

I'm looking to buy a home that I will stay in for 7 years. I have a 200k stock portfolio and the home costs 100k. To reduce on mortgage fees and interest, I've found that Interactive Brokers will give me a variable loan of 100k @ 3.2%
https://www.interactivebrokers.com/en/index.php?f=1595


Seems like it's cheaper than an ARM loan which is ~4.2% and gives me the flexibility of any cash buyer in the real estate market.

And to manage the risk of margin call I can buy super OTM puts to limit by downside. Providing me with a ARM loan for 100bps less than market