Martin Lewis mentions Premium Bonds, fairly regularly on his TV program. He does not recommend, nor does he not recommend. In a recent program, he attempted to explain some mathematics to do with averages, means etc, which I did not understand, to arrive at the figure of £10,000 invested as being the "sweet. spot" at which you begin to approach the 1.4% (or soon to be 1%) return, as you holding increases towards the maximum (£50,000) so to does the chance of a return approaching the published rate. Since April, this year, mine have returned £525, which, I win nothing in Jan, Feb, Mar (2021), will be a return of 1.05%, according to my maths.