He's describing "tax aware borrowing." JP Morgan explains this to their clients here: https://www.jpmorgan.com/jpmpdf/1320698073211.pdf https://www.jpmorgan.com

He's describing "tax aware borrowing." JP Morgan explains this to their clients here: https://www.jpmorgan.com/jpmpdf/1320698073211.pdf https://www.jpmorgan.com/jpmpdf/1320698073211.pdf ; the example on the bottom of page 2 walks through the mechanics. At no point will the client directly use the borrowed money to purchase a home. They will use the borrowed money to purchase securities, which are (by definition) for investment purposes, and for which 100% of margin expense is deductible. Coincidentally, they will also have sold some securities at some other time in the year, and used the proceeds of that sale to buy a home (with cash).