This is not gambling at all.....sure, there is risk; but gambling relies primarily on random chance. Investing in this share does not rely on chance. Sure, there is risk; but there is in every investment. And, unless the company goes bust, you do not lose your stake.
How can a major investment platform go down in the middle of a trading day? I am with AJB & HL, but can't change out of them easily as we have both ISAs and SIPPs with them.