When I was buying funds through fund supermarket time frames given were very vague. Trade was supposed to be executed at next "transaction point", without much description when is it. I am guessing that it is aimed at saving transaction costs by netting as many buy trades from one clients with sell trades from other ones.
How does it work? Are funds bought at fixed points in time or different? Are different supermarkets faster and slower, or is it industry standard in UK? If I understand correctly funds are priced once per day. Are there fund supermarkets that are giving exact day trade is going to be executed? Is buying ETFs faster? Is buying outside ISA faster?