One of the reasons that Y Combinator do not do follow on rounds because, it looks bad if they don't invest in every single one of their investment in the next r

One of the reasons that Y Combinator do not do follow on rounds because, it looks bad if they don't invest in every single one of their investment in the next round. I'm sure there are probably others but ^ is alone is a very good reason not to participate in follow on rounds. However, some of the YC partners are also angels and have made some investments in some of the YC companies in follow on rounds e.g. Priceonomics[1] & Crowdtilt[2] There are others YC companies which the partners have also made investments in, I'm just highlighting two of them. [1] http://techcrunch.com/2012/05/04/priceonomics-seed-round/ http://techcrunch.com/2012/05/04/priceonomics-seed-round/ [2] http://techcrunch.com/2012/05/17/kickstarter-for-groups-and-events-yc-alum-crowdtilt-picks-up-2-1m-from-sv-angel-yc-partners-and-more/ http://techcrunch.com/2012/05/17/kickstarter-for-groups-and-...