For comparison with Avast I use these UK stocks, all in cyber security. LON:AVST, LON:CNS, LON:ECSC, LON:FLX, LON:GBG, LON:SOPH
The companies suggested here for comparisons are usually no good. For Avast, for instance, I use other cyber security companies. In the UK these include Corero, Sophos, ECSC, GB, NCC and Falanx.