There don't seem to be much more than about a dozen chips which can individually command a billion dollar market. Here are the ten biggest (each $1 billion+) markets for individual chip types:
1 Cellular Baseband & Modem
2 PC CPU
3 PC GPU
4 HDD
5 WIFI
6 GPS
7 Video Game ASICs
8 Network LAN
9 Camera
10 STB decoder
This is the fallacy of the financial analyst's 'focus and specialise' mindset - there's no money/market in it! Better to be broader range and able to address multi markets and solutions :-)