1.57% is a lot compared to the ease of just leaving a couple grand in a high-yield savings account. Maybe it's just me but it feels wrong to take out a loan against my portfolio everytime I have to replace my MacBook.

> everytime I have to replace my MacBook.

that's not an emergency! And having a few thousand dollars of liquid cash in a bank account is no brainer.

A real emergency might be like a roof collapse, where you need 10-20k to fix. Or a medical emergency, or a family issue where a fair chunk of change is needed. Using margin is a good way, and is much lower interest than a credit card, provided you have the witherall to pay it back.

You can withdraw on margin?! I suppose in a way that's arguably lower risk, but still seems weird. Also think that's quite nation/broker specific, pretty sure that's not an option with T212 or IG in the UK (which provide margin for trading CFDs and the latter limited options too).

Also shouldn't discount overdrafts, pretty sure mine (as in, available to me) is <1.57% equivalent, and 'arranged' I believe they tend to be cheaper or at least much bigger.

Yup. You can buy a house on margin if you like. With Interactive Brokers' rates as low as 0.75% for large balances it doesn't look like a terrible option vs. an adjustable rate mortgage, if your account balance is high enough that you're not risking a margin call.

If the house is an investment, the margin loan interest may even be tax deductible, without the 750k limit that the mortgage interest deduction has.

I'm curious where you can find a 1.57% overdraft rate? Looking at https://moneyfacts.co.uk/news/banking/revealed-the-cost-of-n..., for example, lists (arranged) rates in the range of 15-40%.

You may be right, I've never had to use one and didn't actually work out the equivalent rate of my unarranged one.