For my son's 18th birthday present, I was thinking of putting some money into a Lifetime ISA. I've read the gov.uk info about them, and the Money Savings Expert (MSE) web page. The promise of what is effectively a guaranteed 25% growth seems attractive. However, there were only a small number of recommended providers on MSE website, with no big name banks mentioned. Our current accounts are with Nationwide, which doesn't seem to offer LISAs. Are they unpopular? Is there any reason to be cautious about them? (For example, are they going to end up as a flash-in-the-pan investment option, like Child Trust Funds, suspended as soon as a different Government takes over, and then passed from pillar to post because the banks can't make any money out of them?)