I'm a bit short of space in my personal statement and there is a bit in it where I talk about how I reached the semi-final of the IFS student investor challenge.Is it worth mentioning this considering I didn't win? Will they not find this impressive. Bearing in mind I am applying for politics (i tried to link the competition to the intertwining nature of economics and politics as disciplines).
If you feel it is useful to your application, then mention it. You could mention key moments and achievements during the process rather than dwelling on the fact you didn't win.