Not sure what type of request you plan to address the bank. They’ll gladly finance the aquisition of a business or a self-employed venture provided their assessment of the venture is that it is profitable. They’ll finance a car and provide a mortgage, for own use or rental property, provided their criteria are met. They’ll probably be reluctant to finance stock purchases unless they’re done through a lombard loan. No idea how they’d address your specific request.
I haven’t gone through a bank for it but private loans are mainly “no question asked” provided you fulfill the affordability criteria. In any case, unless there’s a collateral involved, the amortization rules of the loan would probably make it a very high threshold to meet before it actually becomes beneficial.
I wanted to take out a private loan for stocks investments. It took a 10 year amortization period and 14% planned returns on investment per year to make it work. I’ve deemed the risk way too high to push the endeavour any further. The 3-7% interest rate barely mattered in the global calculation (amortization is what killed it for me).