They're charging interest, just in real pound terms rather than percentages.

You request 'superpowers' to multiply the amount of money you have (a secured loan), and they advise what the monthly fee is and the repayment terms up front.

It's no different to any other secured loan, they just focus on presenting the actual £ amounts rather than % AERs, which is probably clearer for the vast majority of people.

"It's no different to any other secured loan"

It appears to be an unsecured loan. A secured loan is one where the lender takes a lien on (or physical possession of) collateral that can be repossessed or liquidated if the borrower fails to pay back.

"presenting the actual £ amounts rather than % AERs, which is probably clearer for the vast majority of people."

The consumer credit regulators don't agree with you[0]. In the UK, any promotion/solicitation for consumer credit that includes a cost of credit (e.g. the amount of a fee) must also show the APR. The intent of these regulations is to allow offers from different lenders to be compared on a standard measure.

[0] https://www.handbook.fca.org.uk/handbook/CONC/3/5.html

There is a fee of some kind, it's not explained too well - "No weird charges, no complicated maths, no interest. Just a single simple monthly fee."

Robinhood had a similar disruptive position, which earns interest on uninvested cash in customer accounts along with payments from order flow, etc. So I can imagine a similar economy of scale and pass through models w/ Bits.