Since joining Y Combinator as a Visiting Partner last November, the most common question that I have received from folks outside of YC is: “When did YC start investing in bio?” The answer is that bio at YC is not new – YC has been investing in bio companies since 2011. And we are doubling down. Over the last two years, YC has made more seed investments in bio companies than any other investor in the world.

The number of bio companies in each batch has been exponentially increasing, and there are now 141 bio companies funded by YC.

Figure 1. Percent of batch companies that are bio

Figure 2. Total number of bio companies

I define “bio” at YC as anything enabled by biology and anything in healthcare. In healthcare, this includes medical devices, tools, therapeutics, diagnostics, and healthcare IT. Of note, 34% of healthcare-related companies at YC are healthcare IT companies, which means that the majority of healthcare companies at YC are life sciences-based. Other bio-enabled companies include those in agricultural technologies (e.g. farm robots), food technologies (e.g. clean meat), and industrial bio (e.g. biomanufacturing and research tools). Overall, the breakdown of bio companies at YC is 74% healthcare (34% IT, 28% diagnostics, 24% therapeutics, 14% devices), 16% industrial bio, and 10% food and ag tech.

The percentage of bio companies in each batch has been increasing linearly since 2011 (Figure 1). The latest Summer 2018 batch had the highest percentage of bio companies ever, 25%. Since the batch size has also been increasing each year, the total number of companies at YC has been trending at an exponential rate (Figure 2).

In 2011, YC opened its doors to founders starting hard-tech companies, which included bio companies. YC made this decision based on the belief that future billion-dollar companies would increasingly be created by founders working in hard-tech. Since then, what’s driving the trend of an increasing percentage of bio companies batch to batch is less deliberate. YC is all about seeking the best founders and with a foundation of great bio founders, YC has attracted more talented bio founders. YC’s bio alumni now make up a critical mass of amazing founders who pay it forward to new founders.

At the end of the day, YC’s community of founders, partners, staff, and experts is the most valuable part of joining YC, and this community includes a strong bio contingent.