Son wants to buy shares

steampowered

From a pure numbers perspective, the most logical thing to do is to put money into a passive tracker fund.

However, it can be fun to buy individual shares. That can be a great way for people to start getting interested in the stock market, and is a perfectly rational thing for people to do if they are happy to take risk.

While an individual share could easily triple in value, it could also go to zero. He can at least mitigate that risk by buying a few different shares in different industry sectors.

I'm not sure it is even possible to get a share certificate these days, unless you are investing in a private company. Your son will have to buy through a broker. https://www.share.com or https://www.iii.co.uk are good places to start. Something like £15 per trade would be a reasonable price to pay.