For a long time, YC founders (and other investors) have asked us why we don’t continue to financially support our companies after our initial investment by doing our pro rata in future rounds.  Many new investors really like to see the support of existing investors.

There were a lot of reasons why we couldn’t do this in the past. But starting in the Summer of 2014, we added a pro rata provision to our standard investment documents, and starting now, we’re going to aim to support all these companies in future financing rounds by doing our pro rata. We will try to do this for every company in every round with a post-money valuation of $250 million or less.
To make it extra-clear, we’re not going to lead any of these rounds or set the terms, just follow other investors.  And by doing this in every YC company, there will be no signaling issue of us supporting some companies and not others.