Y Combinator, one of best-known Silicon Valley accelerators, has an impressive track record of success. With well-timed investments in Dropbox, Stripe, and Airbnb, the startups in the company’s portfolio are now worth an aggregate of $600 billion in market capitalization.

While Y Combinator has made a clear impact on the tech sector, the company also launched an internal side project in 2007 that would end up becoming highly influential in a different and surprising way.

Its user-powered news aggregator called Hacker News, which is now visited by 20 million people per month, has become a mainstay for entrepreneurs, tech professionals, and venture capitalists around the world. Using a Reddit-like interface, users can upvote and downvote articles that they think have the most relevance to trends and issues affecting the tech sector.

Data Mining For Trends

Today’s charts come to us from Variance Explained, and they help to paint a picture of what topics have been trending on Hacker News over the last 3.5 years.

Using data from over 1 million subject lines, we can see which topics are being mentioned with increasing frequency by the site’s community of technology influencers.

As you can see, words like “AI”, “artificial”, “bot”, “deep”, “neural”, and “learning” are key terms that have growing interest within the community. It shows that the buzz around AI and deep learning is widespread and happening on multiple fronts.

Donald Trump was also a hot topic of debate in Hacker News, as evidenced by the increase in mentions.

Cooling Off

Here are some of the words in the community used with decreasing frequency over the same 3.5 year timeframe:

Over time, as the rubber hits the road, we get to see which ideas have staying power.

Google Glass, as cool as it was, ended up not directly revolutionizing how we use augmented reality. Likewise, Edward Snowden’s revelations about the NSA and surveillance seemed to have also dropped out of discussion.

On the flipside, some of these concepts also seem to have transitioned to the mainstream. Bitcoin and other altcoins, for example, are now more popular than ever before with a market capitalization of over $100 billion. Likewise, iPads, Gmail, and Kickstarter are pretty ubiquitous, but it could be argued that discussion on these topics is now pretty staid for the idea-hungry folks that frequent Hacker News.

Blockchain vs. Bitcoin

It’s also interesting to see the contrasting popularity of two related terms among Hacker News participants.

Bitcoin-related talk, at least on Hacker News, was hot in late-2013 after the price skyrocketed for the first time. The blockchain, on the other hand, took some time to pick up steam among influencers.

Fast-forward to today, and the concept of the blockchain is much more fleshed out.

It took time, but the blockchain is now considered to be a foundational technology that is affecting everything from how how stock markets work, to the proof of ownership for digital assets.