The FTSE100 companies are the 100 largest listed on London Stock Exchange by market capitalisation on that exchange (some have listings on overseas exchanges also) who wish to be in the FTSE100 index. The 250 are the next 250 by the same criteria. Adding the two sets together gives the FTSE350.
There are largecaps listed on London that are not in the FTSE100 for one reason or another, some of these are equally large - Banco Santander, CRH, Brit. Energy, Brambles.
I think the membership of the two indices is adjusted every 3 months by FTSE according to the criteria above, and the new membership can be seen a little time ahead.
Other indices are not always compiled in the same way - e.g. the Dow is a list of 30 NY-listed stocks delected for the purposes of providing a representation of the US economy: the index value is an adjusted average of their share prices in dollars.
There are largecaps listed on London that are not in the FTSE100 for one reason or another, some of these are equally large - Banco Santander, CRH, Brit. Energy, Brambles.
I think the membership of the two indices is adjusted every 3 months by FTSE according to the criteria above, and the new membership can be seen a little time ahead.
Other indices are not always compiled in the same way - e.g. the Dow is a list of 30 NY-listed stocks delected for the purposes of providing a representation of the US economy: the index value is an adjusted average of their share prices in dollars.
