There's lots of relationships whereby the fortunes of one company can be effected by another. For example Tesla and Uber are total dogs snd I could see them imploding. Are there smaller startups that sell services to Tesla and Uber in a significant enough way that they could get hurt too?

Another relationship that has been mentioned before is that of mobile games and google and facebook advertising services. A recession and/or anti-lootbox legislation could harm mobile games, which would reduce ad spend on platforms like facebook/google.