If Swissquote has margin accounts and assuming your loan is within the allowed leverage of your portfolio size, maybe you can simply take on margin loan and withdraw it? This would likely give you the best possible rate (except 0% loan from a friend) for a short term loan. I am not sure if all brokers allow the withdrawal of the margin loaned funds, but some definitely do
Interactive Brokers does lombard loans, you can simply withdraw up to your limit and transfer to your connected bank account. It has served us very well in past.
We were in a similar situation last year, i.e. we wanted to borrow money to buy a car with cash, and we would pay off the loan quickly. We were happy with the terms and conditions of Cembra: low interest rate and the ability to pay off early to save a bit. (i.e. penalties for paying early more than offset what we would have paid in interest)
The big downside is we can’t get them to leave us alone now: cold calling and junk mail all the time, always with the motivation to get us to borrow again. We aren’t even tempted, but it is annoying.
The Facility may only be used by the Client in the form of a debit balance on a current account denominated in Swiss francs (CHF), US dollars (USD) or euro (EUR). The sole purpose of the Limit is to permit the Client to acquire securities via the Bank and it may not be used by the Client for any other purpose.