I don't know if it would help your subscriber who asked about private equity, but I wondered if he was aware that some investment trusts in the UK offer some exposure. For example, Scottish Mortgage has about 20% of its assets in unlisted companies.
There are probably others. Consult the Investment Trust handbook.
(I should say I own shares in Scottish Mortgage)
Thank you for this suggestion which I’m sure will be appreciated by other subscribers. I have also reached out to Jonathan Davis, one of the authors of the Investment Trust Handbook, and I will revert with whatever response he provides.
The Scottish Mortgage Investment Trust is heavily weighted towards US and Chinese tech mega caps. The price pulled back to test the lower side of the range last week and is at least steadying.