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This blog post from YCombinator:

It’s common for startups to build in “stealth” or “secret” and then announce their association with YCombinator ahead of “Demo Day”. Mr Moriarty’s startup Awesound is top of this list that announced the companies in this “batch”: https://www.ycombinator.com/blog/first-fellowship-virtual-demo-day/

For emphasis: “YCombinator” is a small company focused on investing in startups. The aggregate population of all the founders who’ve been “funded by YCombinator” make up the “YC network”, and these founders are called “YC alumni”. YCombinator puts on events for “YC alumni”. The only way to become a member of this network, and therefore get access to bookface and attend in-person events, is to have been funded by YCombinator. Therefore the bar is extremely high (as noted elsewhere in the application, acceptance rate into YCombinator is X.X% – and that’s taking into account the self-selection filter that means only the most ambitious and promising founders apply in the first place).

Mr Moriarty’s esteemed position as a thought leader, mentor and investor, within this already-elite community, is objective evidence that he is operating at the top of the top of his industry. For example, the “Tree Hacks” hackathon that invited him to be the sole Stripe rep and judge at the Stanford hackathon (Feb 15), despite many YC alumni wishing to attend, and despite Stripe not being a sponsor, is a classic example of Mr Moriarty’s individual reputation being prominent even amongst a group of top business operators in Silicon Valley.