yea, it is. but i think it was the Financial Times that "invented" the FTSE 100... which is where the name comes from. I think they basically took the idea of using the top 100 companies as a benchmark for how well the whole of the London Stock Exchange is doing and it got nicknamed the FTSE 100... so basically if the top 100 companies are doing well, so is the rest, if they are doing crap, so are the rest. Hence why when you listen to the finance part of the news they refer to the FTSE 100 going up or down and closing at the a certain rate at the end of day... or something like that.