Maybe worth adding this ETF, which (from their site):
“is a UCITS compliant exchange traded fund that aims to track the Morningstar UK NR Index. The index is designed to represent the performance of the large and mid cap segment of the United Kingdom’s equity market. It covers approximately 97% of the free float-adjusted market capitalisation of the UK.”
The big draw is that its TER is only 0.04%, the lowest I have seen anywhere.
I am new to investing, but it seems like this would be (and is) extremely correlated with Vanguard’s FTSE250, yet the Vanguard one has a 0.10% TER and should be slightly more volatile (since it holds shares in fewer companies than the Lyxor one).
Possible downsides: the Lyxor one is <2 years old, and the Morningstar index that it tracks is less well-known than FTSE.